One of the most common issues machinists face during a drilling operation is hole misalignment. Hole alignment is an essential step in any assembly or while mating cylindrical parts. When holes are properly aligned, the mating parts fit easily in each other. When one of the pieces to the puzzle is inaccurate, however, machinists run into issues and parts can be scrapped. The two types of common misalignment woes are Angular Misalignment and Offset Misalignment.
Angular Misalignment
Angular misalignment is the difference in slope of the centerlines of the holes. When the centerlines are not parallel, a shaft will not be able to fit through the hole properly.
Offset Misalignment
Offset misalignment is the distance between the centerlines of the hole. This is the position of the hole from its true position or mating part. Many CAD software programs will help to identify if holes are misaligned, but proper technique is still paramount to creating perfect holes.
1. Utilize a Spotting Drill
Using a spotting drill is a common way to eliminate the chance of the drill walking when it makes contact with the material. A spotting drill is designed to mark a precise location for a drill to follow, minimizing the drill’s ability to walk from a specific area.
Although using a spotting drill would require an additional tool change during a job, the time spent in a tool change is far less than the time required to redo a project due to a misaligned hole. A misaligned hole can result in scrapping the entire part, costing time and money.
Do you know how to choose the perfect spot drill angle? Learn how in this in-depth guide so you can eliminate the chance of drill walking and ensure a more accurate final product.
2. Be Mindful of Web Thickness
A machinist should also consider the web thickness of the drill when experiencing hole misalignment. A drill’s web is the first part of the drill to make contact with the workpiece material.
Essentially, the web thickness is the same as the core diameter of an end mill. A larger core will provide a more rigid drill and a larger web. A larger web, however, can increase the risk of walking, and may contribute to hole misalignment. To overcome this machining dilemma, machinists will oftentimes choose to use a drill that has a thinned web.
Web Thinning
Also known as a split point drill, web thinning is a drill with a thinned web at the point, which helps to decrease thrust force and increase point accuracy. There are many different thinning methods, but the result allows a drill to have a thinner web at the point while having the benefit of a standard web throughout the rest of the drill body.
A thinner web will:
Be less susceptible to walking
Need less cutting resistance
Create less cutting force
3. Select a Material Specific Drill
Choosing a material specific drill is one of the easiest ways to avoid hole misalignment. A material specific drill design has geometries that will mitigate the specific challenges that each unique material presents. Further, material specific drills feature tool coatings that are proven to succeed in the specific material a machinist is working in.
Drilling an ultra-precise hole can be tough. Material behavior, surface irregularities, and drill point geometry can all be factors leading to inaccurate holes. A Spot Drill, if used properly, will eliminate the chance of drill walking and will help to ensure a more accurate final product.
Choosing a Spot Drill
Ideally, the center of a carbide drill should always be the first point to contact your part. Therefore, a spotting drill should have a slightly larger point angle than that of your drill. Common drill point angles range from 118° to 140° and larger. Shallower drill angles are better suited to harder materials like steels due to increased engagement on the cutting edges. Aluminums can also benefit from these shallower angles through increased drill life. While these drills wear less and more evenly, they are more prone to walking, therefore creating a need for a proper high performance spot drill in a shallow angle to best match the chosen drill.
If a spotting drill with a smaller point angle than your drill is used, your drill may be damaged due to shock loading when the outer portion of its cutting surface contacts the workpiece before the center. Using a drill angle equal to the drill angle is also an acceptable situation. Figure 1 illustrates the desired effect. On the left, a drill is entering a previously drilled spot with a slightly larger angle than its point. On the right, a drill is approaching an area with an angle that is far too small for its point.
Marking Your Spot
A Spotting Drill’s purpose is to create a small divot to correctly locate the center of a drill when initiating a plunge. However, some machinists choose to use these tools for a different reason – using it to chamfer the top of drilled holes. By leaving a chamfer, screw heads sit flush with the part once inserted.
What Happens if I Use a Spot Drill with an Improper Angle?
Using a larger angle drill will allow the drill to find the correct location by guiding the tip of the drill to the center. If the outer diameter of a carbide drill were to contact the workpiece first, the tool could chip. This would damage the workpiece and result in a defective tool. If the two flutes of the drill were slightly different from one another, one could come into contact before the other. This could lead to an inaccurate hole, and even counteract the purpose of spot drilling in the first place.
Avoiding CNC Drill Walking With a Spotting Drill
Few CNC machining applications demand precision like drilling. The diameter hole size, hole depth, part location, and finish are all important and provide little recourse if not up to specifications. That said, accuracy is paramount – and nothing leads to inaccurate final parts faster than drill walking, or the inadvertent straying from a drill’s intended location during the machining process. So how does drill walking occur, and how can one prevent it?
To understand drill walking, think about the act of striking a nail with a hammer, into a piece of wood. Firm contact to a sharp nail into an appropriate wood surface can result in an accurate, straight impact. But if other variables come into play – an uneven surface, a dull nail, an improper impact – that nail could enter a material at an angle, at an inaccurate location, or not at all. With CNC Drilling, the drill is obviously a critical element to a successful operation – a sharp, unworn cutting tool – when used properly, will go a long way toward an efficient and accurate final part.
To mitigate any variables working against you, such as an uneven part surface or a slightly used drill, a simple way to avoid “walking” is to utilize a Spotting Drill. This tool is engineered to leave a divot on the face of the part for a drill to engage during the holemaking process, keeping it properly aligned to avoid a drill from slipping off course.
When Won’t a Spot Drill Work for My Application?
When drilling into an extremely irregular surface, such as the side of a cylinder or an inclined plane, this tool may not be sufficient to keep holes in the correct position. For these applications, flat bottom versions or Flat Bottom Counterbores may be needed to creating accurate features.
https://www.harveyperformance.com/wp-content/uploads/2017/03/Feature-Image-Spotting-Drills-IMG.jpg5251400Tom Pylehttp://www.harveyperformance.com/wp-content/uploads/2018/08/Logo_HarveyPerformanceCompany-4.pngTom Pyle2022-08-25 10:52:002023-10-18 08:19:12Spot Drilling: The First Step to Precision Drilling
When it comes to machining difficult materials like high-silicon aluminums, abrasive copper alloys, and other non-ferrous and aluminum alloys, finding a coating that improves performance and increases tool life can be difficult. When machining in aluminum-based materials, machinists often opt for an uncoated tool due to the sharp cutting edge needed. Uncoated tools may give you the sharpest edge possible, but Helical’s Nplus coating helps combat wear and keep your edge sharp for longer, allowing you to win at the spindle and gain a competitive edge.
What is Helical Solutions’ Nplus Coating?
Helical’s Nplus coating is applied by a Physical Vapor Deposition (PVD) process. This method of coating takes place in a near-vacuum and distributes micron-thick layers evenly onto a properly prepared tool.
Nplus is a premium coating, specially engineered to extend tool life when machining non-ferrous and aluminum alloys.
The above image was taken from Helical Solutions’ Coating Chart.
When Should a Machinist Use Nplus Coating?
When Machining Non-ferrous and Aluminum Alloys
Helical’s Nplus coating is optimized for machining difficult aluminum alloys and other abrasive non-ferrous materials, as its composition doesn’t react with aluminum as some other coatings do. This coating possesses many advantageous qualities, including its high hardness (40 GPa), which provides excellent edge retention to ensure that your tool stays sharp for longer. Also, its high working temperatures (2,012°) and its thickness (1-4 µm) provide further wear resistance when tackling these difficult-to-machine materials.
When Working in High Temperature Non-Ferrous Applications
When machining in many non-ferrous and aluminum alloys, high temperatures can become an issue. Nplus is specially designed to withstand temperatures up to 2,012°, allowing tooling to run at the high temperatures these abrasive materials require, without degrading them.
When Machining Large Production Runs
Machining materials like wrought aluminum, cast aluminum, graphite, and other non-ferrous alloys can quickly end the life of your tool, costing time and money. Nplus coating is specially engineered to extend tool life in these materials, allowing your tool to stay in the spindle for longer. This calls for less tool changes, creating a more efficient process flow in your large production runs.
Helical’s Nplus Coated Tooling
Helical’s 5 Flute End Mills for Aluminum
Introduced in Helical’s Spring 2022 Catalog, Helical’s 5 Flute End Mills for Aluminum are specially engineered for optimal performance in High Efficiency Milling (HEM) of aerospace aluminum alloys and other non-ferrous alloys. They’re offered in two unique styles, both fully stocked in Helical’s Nplus coating:
Also introduced in Helical’s Spring 2022 catalog, this offering of Multi-Axis Finishers feature a specially defined profile for massive reductions in cycle times and vastly improved surface finish when machining aluminum. They’re offered in 3 styles, all fully stocked in Helical’s Nplus coating to ensure excellent finish in abrasive aluminums and extended tool life in a wide variety of non-ferrous materials.
Proper tool coating plays a large role during the selection of a CNC cutting tool. At Harvey Tool, coatings are optimized for specific materials and alloys to ensure the highest tooling performance, possible. Each coating offers a unique benefit for the cutting tool: increased strength, enhanced lubricity, heat resistance, and wear mitigation, just to name a few.
In Benefits of Tool Coatings, the method of applying coatings to tools is examined. In this post, we’ll take a closer look at each Harvey Tool coating to examine its key properties, and to help you decide if it might add a boost to your next CNC application.
Harvey Tool offers a wide range of tool coating options for both ferrous and exotic materials, as well as non-ferrous and non-metallic materials. In the Harvey Tool catalog, coatings are often denoted in a -C# at the end of the product part number.
Harvey Tool Coatings for Ferrous and Exotic Materials
TiN
TiN, or Titanium Nitride (-C1), is a mono-layer coating meant for general purpose machining in ferrous materials. TiN improves wear resistance over uncoated tools and aids in decreasing built-up edge during machining. This coating, however, is not recommended for applications that generate extreme heat as its max working temperature is 1,000 °F. TiN is also not as hard as AlTiN and AlTiN Nano, meaning its less durable and may have a shorter tool life.
AlTiN, or Aluminum Titanium Nitride (-C3), is a common choice for machinists aiming to boost their tool performance in ferrous materials. This coating has a high working temperature of 1,400 °F, and features increased hardness. AlTiN excels in not only dry machining, due to its increased lubricity, but also in machining titanium alloys, Inconel, stainless alloys, and cast iron. To aid in its high heat threshold, the aluminum in this coating coverts to aluminum oxide at high temperatures which helps insulate the tool and transfer its heat into the formed chips.
AlTiN Nano or Aluminum Titanium Nitride Nano (-C6) is Harvey Tool’s premium coating for ferrous applications. This coating improves upon AlTiN by adding silicon to further increase the max working temperature to 2,100 °F while also increasing its hardness for increased tool life during demanding applications. Due to its penchant for demanding applications, AlTiN is recommended for hardened steels, hardened stainless, tool steels, titanium alloys, and aerospace materials. These applications often create high levels of heat that AlTiN Nano was designed to combat.
Note: AlTiN and AlTiN Nano are not recommended for use in Aluminum or Aluminum Alloys due to their high affinity to those materials.
Tool Coatings for Non-Ferrous and Non-Metallic Materials
TiB2
TiB2, or Titanium Diboride (-C8), is Harvey Tool’s “bread and butter” coating for non-abrasive aluminum alloys and magnesium alloys, as it has an extremely low affinity to aluminum as compared to other coatings. Aluminum creates lower working temperatures than ferrous materials, so this coating has a max working temperature of of a suitable 900 °F. TiB2 prevents built-up edge and chip packing, further extending its impressive tool life. TiB2 is not recommended for abrasive materials as the carbide is slightly weakened during the coating process. These materials can cause micro fractures that may damage the tool at high RPMs.
TiB2 can be found on a wide variety of Harvey Tool 2 and 3 flute tools as the premium option for high performance in aluminum alloys.
ZrN, or Zirconium Nitride (-C7), is a general-purpose coating for a wide variety of non-ferrous materials, including abrasive aluminum alloys. This tool coating is a lower cost alternative to diamond coatings, while still boasting impressive performance through its high hardness levels and overall abrasion resistance. ZrN has a max working temperature of 1,110 °F with strong lubricity in abrasive alloys. This coating is best suited for abrasives, such as brass, bronze, and copper, as well as abrasive aluminum alloys that should not be used with TiB2.
CVD Diamond, or Crystalline CVD Diamond, is a process where the coating is grown directly onto the carbide end mill. This process dramatically improves hardness over other coatings, improving tool life and abrasion resistance while also allowing for higher feed rates. The trade-off for increased wear resistance is a slight rounding of the cutting edge due to the coating application. Due to its increased wear resistance, CVD is best suited for highly abrasive materials such as graphite, composites, green carbide, and green ceramics. Similarly, these tool coatings have a max working temperature of 1,100 °F, meaning they are not well suited for ferrous applications.
Harvey Tool’s CVD Diamond Coating Options:
Amorphous, CVD 4 μm, CVD 9 μm, PCD Diamond
CVD Diamond (4 μm)
The 4 μm is thinner than the 9 μm allowing for a sharper cutting edge, which in effect leaves a smoother finish.
CVD Diamond 9 μm)
The 9 μm CVD tool coating offers improved wear resistance over the 4 μm CVD and Amorphous coatings due to its increased coating thickness.
Amorphous Diamond
Amorphous Diamond (-C4) is a PVD diamond coating which creates an exceptionally sharp edge as compared to CVD. This coating aids in performance and finish in abrasive non-ferrous applications, as it allows for greatly improved abrasion resistance during machining, while still maintaining a sharp cutting edge necessary for certain abrasives. Due to the thinness of the coating, edge rounding is prevented in relation to CVD diamond tooling. Amorphous Diamond is best suited for use in abrasive plastics, graphite, and carbon fiber, as well as aluminum and aluminum alloys with high silica content, due to their abrasiveness. The max working temp is only 750 °F, so it is not suited for use in ferrous machining applications.
PCD Diamond, or Polycrystalline Diamond, is a tool coating that is brazed onto the carbide body. In comparison to the other diamond coatings, PCD does not face the same challenges of other coatings as it pertains to rounded cutting edges, as these edges are ground sharp. PCD has the edge benefits of Amorphous Diamond with the abrasion resistance of CVD Diamond. PCD is the thickest diamond layer offered by Harvey Tool, and excels due to its incredible hardness and abrasion resistance. This tool is best suited for all forms of abrasive, non-ferrous materials including abrasive plastics, graphite, carbon fiber, and composites. Similar to the other non-ferrous tool coatings, PCD is not suited for ferrous applications due to its working temperature of 1,100 °F.
When deciding on a coating for your application there are many factors to be considered. Different coatings often cross several applications with performance trade-offs between all of them. Harvey Tool offers a “Material Specific Selection” that allows users to choose tooling based upon what materials they are working with. Further, Harvey Tool’s technical team is always a phone call away to help in finding the right tool for your specific applications at 1-800-645-5609. Also, you can contact Harvey Tool via e-mail.
When navigating Titan USA’s offering of carbide drills, it is imperative to understand the key differences among the three carbide drill styles: Jobber Length, Stub Length, and Straight Flute Drills. The right drill for your application depends on, among other factors, the material you are working in, the job requirements, and the required accuracy.
PRO TIP:
Chip evacuation can be an obstacle for hole making. Pecking cycles can be used to aid in chip removal. Peck cycles are when the drill is brought in and out of the hole location, increasing depth each time until the desired depth is reached. However, pecking cycles should only be used when necessary; this process increases cycle time and subjects the tool to added wear from the repeated engaging and disengaging.
Jobber Length Drills
A carbide Jobber Length Drill is the standard general-purpose drill within Titan USA’s offering. It has a long flute length and an included angle of 118o. These drills are great for general purpose drilling where the tolerances are not as tight as the Stub Drill or Straight Flute Drill. Due to the length of these drills, however, they will be more affected by any lack of rigidity in the set up and can have higher runout, or straying from a desired location, during the drilling operation.
PRO TIP:
To achieve high accuracy and great finish, consider utilizing a Reamer. Reamers are designed to remove a finite amount of material but bring a hole to a very specific size. To do this, first drill 90% – 94% of the desired hole diameter with a Jobber Drill. After 90% – 94% of the material is removed, go in for a finishing pass with a Reamer. Reaming tools are highly accurate and leave a beautiful finish.
Stub Length Drills
Titan USA carbide Stub Length Drills have a shorter flute length, wider included point angle, and a significant drop in helix angle, when compared to Jobber Length Drills. The shorter length and wider tip create for a more rigid tool and, in turn, more accurate holes. The stub drill is the best option when drilling with tight tolerances on shallower holes.
Straight Flute Drills
Carbide Straight Flute Drills have the smallest core of the three drill types mentioned within this post. Titan USA offers Straight Flute Drills with 2 flutes and a 140o included angle. These drills are designed for hole making in materials that create short chips. Materials in which the Straight Flute Drill typically performs best include cast aluminums and cast irons, as well as copper. In addition, this type of drill can work very well in high hardness materials, but the core diameter should first be adjusted to accommodate the increased hardness. For these difficult to machine materials, casting the part with a core hole and then opening it up with the Straight Flute is a great option. This removes some of the stress caused by chip removal and allows for the drill to do what it does best.
Chip removal can be more difficult in this style of carbide drill because the chips are not guided along a helix. With helix flutes, the motion of chip removal is mostly continuous from their initiation point, through the flute valleys, and finally out of the flute valleys. The helix creates a wedge which helps push the chips along, but the straight flute does not have that. It interrupts that natural turning motion created by the drill face which can affect chip evacuation. Due to the interruption in motion this type of drill is better suited for applications involving chips of smaller size.
PRO TIP:
Helix drills create multiple different forces on the part, which can create micro imperfections. The Straight Flute Drills do not create those forces, so the finish is much more consistent down to the micro level. The margins of the Straight Flute Drill also burnish the inside of the hole as they spin, which improves the finish as well. When comparing the Straight Flute Drill to a helix drill, the length of the overall contact point is much shorter in the Straight Flute Drill, and has less heat generation. The decreased heat will also reduce the probability of work hardening.
Selecting Your Perfect Titan USA Carbide Drill
Selecting the correct carbide drill for your application is a crucial step in hole making. The Jobber Drill is a great general-purpose drill and should be utilized in applications requiring long reach. The Stub Drill increases the rigidity with its shorter length of flute, allowing it to drill with higher accuracy. Applications which involve tight tolerances and more shallow holes can be done with the Stub Drill for high-quality results. Lastly, for difficult to machine and hard materials, the Straight Flute Drill is the perfect solution. When the core diameter and chip evacuation is properly addressed, the Straight Flute Drill produces beautifully consistent surface finish and extremely tight tolerances. Similarly, Titan USA offers its carbide drills in both an uncoated option, and AlTiN coating. Traditionally, uncoated tools are general purpose workhorses in a wide variety of materials both ferrous and non-ferrous. AlTiN or Aluminum Titanium Nitride is an enhanced coating specifically made for ferrous materials that extends tool life and performance across a wide range of steels and their alloys.
For more information on Titan USA Drills, and to view its full selection, click here.
Did you know that, along with supplying the machining industry with premier turning tools, Micro 100 also fully stocks tool holders for its proprietary Micro-Quik Quick Change Tool Holder System? In fact, Micro 100’s Spring 2021 Product Catalog introduced new “headless” style tool holders, which are revolutionizing the machine setup process for turning operations.
This “In the Loupe” guide is designed to provide you with insight for navigating Micro 100’s offering, and to help you select the optimal holder style for your operation.
Understanding Micro 100’s Micro-Quik
Micro 100’s Micro-Quik is unlike any other tool change system you may have seen from other tool manufacturers because of its incredible axial and radial repeatability and its ease of use. This foolproof system delivers impressive repeatability, tip-to-tip consistency, and part-to-part accuracy, all the while resulting in tool changes that are 90 % faster than conventional methods.
In all, a tool change that would regularly take more than 5 minutes is accomplished in fewer than 30 seconds.
Micro 100 Quick Change Tool Holder Selection
Straight Style, Headless Tool Holders
When using a straight style tool holder, you will enjoy significantly enhanced versatility during the machine set up process. These holders are engineered specifically for use in any Swiss, standard lathe, or multi-function lathe, and allow for adjustable holder depth in a tooling block. Radial coolant access ports provide easier access to coolant and the ability to utilize coolant through functionality in tooling blocks that share a static and live tool function, and cannot be plumbed through the back of the holder. Further, their headless design allows for installation through the backside of the tooling block in machines where the work envelope is limited, allowing for a simplified installation process.
Created by Harvey Performance Company Application Engineers, the following videos outline the simple process for inserting each style of Micro 100 Straight Tool Holder into a tooling block.
In the video, you’ll notice that the first step is to place your Micro-Quik tool in this quick change holder, and align it with the locating pin. Then, tighten the locating and locking screw into the whistle notch. This forces the tool against the locking pin, and allows for repeatable accuracy, every time. From there, the quick change tool holder can be installed as a unit into a tooling block. When desired tool position is achieved, set screws can be tightened to lock the holder in place.
This unique Micro 100 quick change tool holder style is plumbed and ported, allowing for enhanced versatility and coolant delivery efficiency. The setup process using this style of holder is also simple. First, place your Micro 100 quick change tool into the holder, and align it with the locating pin. From there, tighten the locating and locking screw into the whistle notch, forcing the tool against the locating pin and allowing for repeatable accuracy, every time. When plumbed coolant is being used, remove the plumbed plug in the back of the holder, and connect the appropriate coolant adapter and line. Then, the holder can be installed as a unit into the tooling block and locked into place with set screws.
When using ported coolant, make sure that the coolant plug in the back of the holder is tightly installed. Then, be sure to only use one of the radial ports. Simply plug the two that aren’t in use. Install the provided porting adapter to allow for coolant access. Porting options allow for coolant capabilities in machine areas where coolant is not easily accessible.
Headed Tool Holders
Micro 100’s original quick change tool holder for its Micro-Quik system, this style of tool holder for lathe applications features a unique “3 point” locking and locating system to ensure repeatability. When conducting a tool change with this tool holder style, you must follow a simple, 3-step process:
Loosen the tool holder’s set screw
Remove the used tool from the holder
Insert the new tool and retighten the set screw
These headed holders are plumbed through the back of the holder for NPT coolant connection and are available in standard length and long length styles.
For twin spindle and Y-axis tooling block locations, Micro 100 fully stocks a double-ended modular system. Similar to its single-ended counterparts, this modular is headless, meaning it enhances machine access during the tool block installation process, and the holder depth can be adjusted while in the block. Because this system is double-ended, however, there is obviously no plumbed coolant option through the end of the tool. Instead, coolant is delivered via an external coolant port, the adapter for which is included in the purchase of the modular system. Right hand and left hand tool holders are designed so the set screws are facing the operator for easy access. Both right and left hand styles are designed for right hand turning.
Enjoy Quick Change Tool Holding Confidence & Ease of Use
When opting for a quick change system, machinists long for simplicity, versatility, and consistency. Though many manufacturers have a system of their own, Micro 100’s Micro-Quik sets itself apart with axial and radial repeatability, and tip-to-tip consistency. Further, Micro 100 fully stocks several quick change tool holder options, allowing a machinist to select the style that best fits their application.
Micro100 also manufactures and stocks a wide variety of boring tools for the Micro-Quik. Click here to learn more.
For more information on selecting the appropriate quick change tool holder for your job, view our selection chart or call an experienced Micro 100 technical engineer at 800-421-8065.
https://www.harveyperformance.com/wp-content/uploads/2021/07/Featured-Image-Quick-Change-Holders-IMG.jpg5251400Harvey Performance Companyhttp://www.harveyperformance.com/wp-content/uploads/2018/08/Logo_HarveyPerformanceCompany-4.pngHarvey Performance Company2021-07-19 11:28:002023-09-27 10:41:48Understanding Key Qualities in Micro 100’s Offering of Micro-Quik Quick Change Tool Holders
Unlike most CNC cutting tools, Thread Forming Taps, otherwise known as Form Taps, Forming Taps, or Roll Taps, work by molding the workpiece rather than cutting it. Because of this, Form Taps do not contain any flutes, as there is no cutting action taking place, nor are there any chips to evacuate. Below are 8 unique facts of Thread Forming Taps (and some may surprise you).
1. Chips Aren’t Formed
When using a Form Tap, chips are not formed, nor is any part material evacuated (Yes, you read that right). With thread forming, the tool is void of any flutes, as chip evacuation is not a concern. Form Taps quite literally mold the workpiece, rather than cut it, to produce threads. Material is displaced within a hole to make way for the threads being formed.
2. Cutting Oils Allow for Reduced Friction & Heat Generation
Did you know that Thread Forming Taps require good lubrication? But why is that the case if chips are not being evacuated, and how does lubrication enter the part with such a limited area between the tool and the perimeter of the hole being threaded? Despite the fact that chips aren’t being formed or evacuated, cutting oils aid the Form Tap as it interacts with the part material, and reduces friction and heat generation. Lube vent grooves are narrow channels engineered into the side of Forming Taps that are designed to provide just enough room for lubricant to make its way into – and out of – a part.
3. Only Certain Materials Are Recommended for Thread Forming
Not all materials are well suited for Thread Forming Taps. In fact, attempting to use a tap in the wrong material can result in significant part and tool damage. The best materials for this unique type of operation include aluminum, brass, copper, 300 stainless steel, and leaded steel. In other words, any material that leaves a stringy chip is a good candidate for cold forming threads. Materials that leave a powdery chip, such as cast iron, are likely too brittle, resulting in ineffective, porous threads.
4. Threads Produced Are Stronger Than Conventional Tapping Threads
Thread forming produces much stronger threads than conventional tapping methods, due to the displacements of the grain of the metal in the workpiece. Further, cutting taps produce chips, which may interfere with the tapping process.
5. Chip Evacuation is Never a Concern With Thread Forming
In conventional tapping applications, as with most machining applications, chip evacuation is a concern. This is especially true in blind holes, or holes with a bottom, as chips created at the very bottom of the hole oftentimes have a long distance to travel before being efficiently evacuated. With form taps, however, chip removal is never a concern.
6. Form Taps Offer Extended Tool Life
Thread Forming Taps are incredibly efficient, as their tool life is substantial (Up to 20x longer than cutting taps), as they have no cutting edges to dull. Further, Thread Forms can be run at faster speeds (Up to 2x faster than Cutting Taps).
Pro Tip: To prolong tool life even further, opt for a coated tool. Titan USA Form Taps, for example, are fully stocked in both uncoated and TiN coated styles.
7. A Simple Formula Will Help You Find the Right Drill Size
When selecting a Tap, you must be familiar with the following formula, which will help a machinist determine the proper drill size needed for creating the starter hole, before a Thread Forming Tap is used to finish the application:
Drill Size = Major Diameter – [(0.0068 x desired % of thread) / Threads Per Inch] Drill Size (mm) = Major Diameter – [(0.0068 x desired % of thread x pitch (mm)]
8. Thread Forming Taps Need a Larger Hole Size
Thread Form Taps require a larger pre-tap hole size than a cutting tap. This is because these tools impact the sides of the hole consistently during the thread forming process. If the pre-tap hole size is too small, the tool would have to work too hard to perform its job, resulting in excessive tool wear, torque, and possible breakage.
As an example, a ¼-20 cut tap requires a #7 drill size for the starter hole, whereas a ¼-20 roll tap requires a #1 drill size for 65% thread.
With recent advancements in 3D printing capabilities, it is becoming easier for manufacturers to use additive manufacturing to create parts from a wide variety of materials, including polymers like ABS, TPE, and PLA as well as carbon fiber composites, nylon, and polycarbonates. Even pricey metals like Titanium, Stainless Steel, and Inconel are becoming increasingly common in the world of additive manufacturing as well.
There is no doubt that the additive manufacturing space will continue to develop and grow in the coming years, but will it render subtractive manufacturing methods like CNC Machining obsolete? Absolutely not. In fact, precision CNC machining is likely more important to the additive manufacturing process than you may think, as a new process called “hybrid manufacturing” is quickly taking hold in the industry.
3D printing of metal parts is becoming more common, but subtractive manufacturing is an important part of manufacturing precision additive parts.
Additive Manufacturing vs. Subtractive Manufacturing
Before implementing a hybrid manufacturing approach, it is important to understand the pros and cons of each method. Here is a quick breakdown of both additive and subtractive manufacturing, and the benefits and drawbacks of each.
Additive Manufacturing
Subtractive Manufacturing
Adds material layers to create parts
Removes material layers to create parts
Slower process, better for small production runs
Faster process, better for large production runs
Better for smaller parts
Better for larger parts
Rough surface finish that requires significant post-operation finishing
More definied surface finish with minimal post-operation finishing required
Less precise part tolerances
Able to hold extremely precise part tolerances
Cheaper material costs
More expensive material costs
Less material waste
More material waste
Intricate details easier to create
Intricate details can require complex programs and additional capabilities (5 axis)
Using CNC Machining to Create Precise 3D Printed Parts
Looking at the chart above, you will notice that one of the key differences between additive manufacturing and subtractive manufacturing is the surface finish and tolerances that can be achieved with each method. This is where a hybrid approach to additive manufacturing can be extremely beneficial.
As parts come off the printer, they can be quickly moved into a CNC machine with a program designed for part completion. The CNC machine will be able to get 3D printed parts down to the tight tolerances required by many industries and reach the desired surface finish. Advanced finishing tools and long reach, tapered tools from brands like Harvey Tool can easily machine the tight geometries of 3D printed parts, while extremely sharp diamond-coated tooling and material-specific tools designed for plastics and composites can work to create a beautiful, in-tolerance finished part regardless of the material.
Long reach tools can easily machine hard to reach, intricate part details on 3D printed parts.
By designing a workflow like this in your shop, you can spend less time worrying about the precision of printed parts by adding in subtractive operations to keep material costs low, create less waste, and keep parts in tight tolerances for precision machining excellence.
Using 3D Printing to Increase CNC Machining Efficiency
If your shop is focused completely on subtractive manufacturing methods, you are probably thinking that there is no need for an additive option in your shop. Can’t a CNC machine create everything a 3D printer can, and in less time? Not necessarily. Again, by using the two methods together and taking a hybrid approach, you may be able to lower your manufacturing and material costs.
For example, you could machine the bulk of a part with typical subtractive machines, which would likely take a very long time using additive methods. Then you can go back to that part with a 3D printer to add intricate features to the part that may take complex programming and hours of planning on a subtractive machine. An impeller is a great example, where the bulk of that part can be machined, but the tricky fins and blades could be printed onto the part, and then finished back on the CNC machine.
3D printed impeller waiting for finishing operations
The ability of additive machines to literally “add-on” to a part can also make for a cheaper approach to part design. Instead of using expensive materials like Inconel or Titanium to machine an entire part, portions of the part that do not require extreme heat resistance could be machined out of cheaper steel, while the heat resistant portions using expensive materials can be added later through additive methods.
Hybrid Manufacturing Machines
As hybrid manufacturing workflows become more popular, so do new hybrid manufacturing machines. These hybrid machines are all-in-one machines where both additive and subtractive manufacturing can be performed in a single setup. Many of these machines offer metal 3D printing as well as multi-axis machining capabilities, ready for even the most complex parts thrown their way. With a bit of customization, large-scale 3D printing machines or CNC mills can be retrofit to allow for hybrid manufacturing with add-ons from companies like Hybrid Manufacuring Technologies.
Example of a hybrid machine add-on from Hybrid Manufacturing Technologies, featuring 3D printing spindles and milling tools in the same machine carousel.
As manufacturing and design techniques get progressively “smarter” with CAM/CAD programs offering generative design and artificial intelligence, these hybrid machines could become a new standard in high-end machine shops working in advanced manufacturing industries like aerospace, medical, defense, and the mold, tool & die market.
Overall, in 2021 we are still early on in this new revolution of hybrid machining and advanced design methods, but it is important to understand the role that adding a CNC machine could have in your additive-focused shop, and vice versa. By combining additive and subtractive together, shops can mitigate the cons of each method and take full advantage of the benefits of having both options available on the shop floor.
https://www.harveyperformance.com/wp-content/uploads/2021/02/Hybrid-Manufacturing-Featured-Image.jpg4351155Harvey Performance Companyhttp://www.harveyperformance.com/wp-content/uploads/2018/08/Logo_HarveyPerformanceCompany-4.pngHarvey Performance Company2021-03-09 15:16:012021-11-05 13:21:00CNC Machining & 3D Printing: A Hybrid Approach to Precision Manufacturing
In turning operations, the tool is stationary while the workpiece is rotating in a clamped chuck or a collet holder. Many operations are performed in a lathe, such as facing, drilling, grooving, threading, and cut-off applications. it is imperative to use the proper tool geometry and cutting parameters for the material type that is being machined. If these parameters are not applied correctly in your turning operations, built-up edge (BUE), or many other failure modes, may occur. These failure modes adversely affect the performance of the cutting tool and may lead to an overall scrapped part.
Common Types of Tool Failure
When inspecting a cutting tool under a microscope or eye loupe, there are several different types of turning tool failure modes that can be apparent. Some of the most common modes are:
Normal Flank Wear: The only acceptable form of tool wear, caused by the normal aging of a used cutting tool and found on the cutting edges.
This abrasive wear, caused by hard constituents in the workpiece material, is the only preferred method of tool wear, as it’s predictable and will continue to provide stable tool life, allowing for further optimization and increased productivity.
Cratering: Deformations found on the cutting face of a tool.
This tool mode is a chemical and heat failure, localized on the rake face area of the turning tool, or insert. This failure results from the chemical reaction between the workpiece material and the cutting tool and is amplified by cutting speed. Excessive Crater Wear weakens a turning tool’s cutting edge and may lead to cutting edge failure.
Chipping: Breaking of the turning tool along its cutting face, resulting in an inaccurate, rough cutting edge.
This is a mechanical failure, common in interrupted cutting or non-rigid machining setups. Many culprits can be to blame for chipping, including machine mishaps and tool holder security.
Thermal Mechanical Failure (Thermal Cracking): The thermal cracking of a cutting tool is due to significant swings in machining temperature.
When turning, heat management is key. Too little or too much heat can create issues, as can significant, fast swings in temperature (repeated heating and cooling on the cutting edge). Thermal Mechanical Failure usually shows in the form of evenly spaced cracks, perpendicular to the cutting edge of the turning tool.
Built-Up Edge (BUE): When chips adhere to the cutting tool due to high heat, pressure, and friction.
Effects of Built-Up Edge in Turning Application
What Is BUE In Machining?
A built-up edge is perhaps the easiest mode of tool wear to identify, as it may be visible without the need for a microscope or an eye loupe. The term built-up edge means that the material that you’re machining is being pressure welded to the cutting tool. When inspecting your tool, evidence of a BUE problem is material on the rake face or flank face of the cutting tool.
This condition can create a lot of problems with your machining operations, such as poor tool life, subpar surface finish, size variations, and many other quality issues. The reason for these issues is that the centerline distance and the tool geometry of the cutting edge are being altered by the material that’s been welded to the rake or flank face of the tool. As the BUE condition worsens, you may experience other types of failures or even catastrophic failure.
Causes of Built-Up Edge in Turning Applications
Improper Tooling Choice
Built-Up Edge is oftentimes caused by using a turning tool that does not have the correct geometry for the material being machined. Most notably, when machining a gummy material such as aluminum or titanium, your best bet is to use tooling with extremely sharp cutting edges, free cutting geometry, and a polished flank and rake face. This will not only help you to cut the material swiftly but also to keep it from sticking to the cutting tool.
Using Aged Tooling
Even when using a turning tool with correct geometry, you may still experience BUE. As the tool starts to wear and its edge starts to degrade, the material will start building up on the surface of the tool. For this reason, it is very important to inspect the cutting edge of a tool after you have machined a few parts, and then randomly throughout the set tool life. This will help you identify the root cause of any of the failure modes by identifying them early on.
Built-up edge can be caused from running a tool at incorrect cutting parameters. Usually, when BUE is an issue, it’s due to the speed or feed rates being too low. Heat generation is key during any machining application – while too much heat can impact a part material, too little can cause the tool to be less effective at efficiently removing chips.
4 Simple Ways to Mitigate Built-Up Edge in Turning Applications
Chipbreaker Tooling
When selecting a tool, opt for free cutting, up sharp geometries with highly polished surfaces. Selecting a tool with chipbreaker geometry will also help to divide chips, which will help to remove it from the part and the cutting surface. Boring bars with chipbreaker geometry allow for maximum control over the chips leading to freer cutting when turning.
Correct Speeds and Feeds
Be confident in your application approach and your running parameters. It’s always important to double-check that your speeds and feeds are appropriate for your turning application. Ensure the condition of your machine is optimal as older machines used for abrasive materials may display backlash. Consult your tooling manufacturer for recommended speeds and feeds and to prevent from aggressively running your machine more than it can handle.
Coolant Usage
When coolant is directed towards a part, it can evacuate chips and aid in preventing high temperatures from melting onto the cutting edge. Thus, BUE is less likely to occur when coolant is utilized. Make sure the coolant is focused on the cutting edge and increase the coolant concentration amount.
Tool Coatings
Opt for a coated insert, as tool coatings are specifically engineered for a given set of part materials, and are designed to prevent common machining woes. Coatings are designed to minimize the impact of cutting forces and to keep tool failure at bay. Machinists must select the right material specific coating for their turning operations in order to promote the life of their tools.
https://www.harveyperformance.com/wp-content/uploads/2020/12/Feature-Image-BUE-IMG-2.jpg5251400Harvey Performance Companyhttp://www.harveyperformance.com/wp-content/uploads/2018/08/Logo_HarveyPerformanceCompany-4.pngHarvey Performance Company2020-12-10 16:51:402023-11-17 15:11:44Causes & Effects of Built-Up Edge (BUE) in Turning Applications
Making a manual tool change on any CNC machine is never a
timely or rewarding process. Typically, a tool change in a standard holder can
take up to 5 minutes. Add that up a few times, and suddenly you have added
significant minutes to your production time.
As CNC machine tool and cutting tool technology has advanced, there are more multi-functional tools available to help you avoid tool changes. However, sometimes it just isn’t feasible, and multiple tool changes are needed. Luckily, Micro 100 has developed a revolutionary new method to speed up tool changes significantly.
What is the Micro-Quik Tooling System?
Developed in Micro 100’s world-class grinding facility in Meridian, Idaho, the Micro 100 Micro-Quik tooling systemis held to the same standards and tight tolerances as all of the Micro 100 carbide tooling.
The quick change tooling system allows for highly repeatable tool changes that save countless hours without sacrificing performance. This system combines a unique tool holder with a unique tool design to deliver highly repeatable and accurate results.
Each quick change tool holder features a locating/locking set screw to secure the tool and a locating pin which helps align the tool for repeatability. Removing a tool is as simple as loosening the set screw and inserting its replacement.
During tool changes, the precision ground bevel on the rear of the tool aligns with a locating pin inside the tool holder. The distance from this locational point to the tip of the tool is highly controlled under tight tolerances, meaning that the Micro-Quik tooling system ensures a very high degree of tool length and centerline repeatability. The “L4” dimension on all of our quick change tools, as seen in the image above, remains consistent across the entire product line. Check out the video below for a demonstration of the Micro 100 Micro-Quik system in action!
Quick Change Tooling Benefits
The most obvious benefit to using Micro 100’s Micro-Quik Quick Change Tooling System is the time savings that come with easier tool changes. By using the quick change holders in combination with quick change tooling, it is easy to reduce tool changes from 5 minutes to under 30 seconds, resulting in a 90% decrease in time spent swapping out tools. This is a significant benefit to the system, but there are benefits once the tool is in the machine as well.
As mentioned above, the distance from the locational point on each tool shank to the tip of the tool is highly controlled, meaning that regardless of which type of tool you insert into the holder, your stick out will remain the same. This allows you to have confidence in the tooling and does not require additional touch offs, which is another major time saver.
By removing additional touch-offs and tool changes from your workflow, you also reduce the chances for human or machine error. Improper touch-offs or tool change errors can cause costly machine crashes and result in serious repairs and downtime. With the Micro 100 Micro-Quik Quick Change Tooling System, initial setups become much easier, allowing you to hit the cycle start button with total confidence for each run.
By making a few simple changes to your tool holding configurations and adopting the Micro-Quik system, your shop can save thousands in time saved, with less machine downtime and increased part production. To learn more about the Micro 100 Micro-Quik cutting tools and tool holders, please visit Micro 100.
https://www.harveyperformance.com/wp-content/uploads/2020/04/Feature-Image-Quick-Change-Tooling-IMG.jpg5251400Harvey Performance Companyhttp://www.harveyperformance.com/wp-content/uploads/2018/08/Logo_HarveyPerformanceCompany-4.pngHarvey Performance Company2020-04-10 08:00:002023-10-05 08:58:22Save Time With Quick Change Tooling
