In the Loupe TV: Minimizing Chips With Chipbreakers
To aid chip evacuation, Chipbreaker End Mills feature a notched profile along the cutting edge that break down long chips into smaller, more manageable pieces. In addition to improving chip control and reducing cutting resistance, these tools also help in decreasing heat load within the chips. This delays tool wear along the cutting edge and improves cutting performance. Join In The Loupe TV’s “Cutting Tool Counselor,” Don Grandt, as he explains all of the numerous benefits that chipbreaker end mills can provide you at the spindle.
Thanks, that was interesting. I run a manual milling machine, usually cutting stainless steel. When cutting a material face that is not more than about a half inch high, I use a plain flute stub mill and the chips are not long enough to cause a problem. However any thicker than that, and the chips immediately form a birds nest that gets in the way. What I need is a chip length short enough that the chips can fall into each other in a compact form. I do NOT need the chips to be dust that is impossible to keep from sticking into my fingers and difficult to see to pull them out! So the ideal spacing of notches along the edge will be about 1/3 of an inch, or at least making chips that length.
Also, the cutting action is at least partly shearing or slicing metal from the edge, not a straight chisel function, with a spiral flute such as 30 to 45 degrees. The edge partly slides along the cut. This should affect the ideal notch shape, including the angle of the notch to the edge, and the way the next tooth handles material not removed by the notch. A very small notch can be sufficient to break the chip instead of completely discontinuing the cut.
I get a very good finish from your chip breaker end mills. I really cannot see any difference at all from a plain edge. That is, unlike the chip breaker end mill that I made by accident when insufficiently secured work came out of the vise and left little notches in my plain edge end mill. I was getting the long “sword” chips that I do not like. After the accident, the chips were all short the way I like them! Unfortunately, the accidental notches were not properly staggered between edges, so it leaves excessive lines along the surface I am cutting.