Chipformer (ch p fr m ..r) n
A geometric shape on the rake face of a cutting tool. The shape forms the chip during chip formation in a shape which controls the chip.
Chipformers differ from chipbreakers. (A chipbreaker bends the chip after it has been cut causing it to break.) A chipformer, forms the chip for the purposes of chip control. Chipformers can be applied to a variety of cutting tools, producing a controlled chip shape using less; power, heat and less force vs. chipbreakers. The main mechanism at work is a variation in rake angle along the shear zone. This produces a thick or thinner portion of the chip. The thin portion of the chip wants to travel faster than the ticker portion, and as a result the differential stress causes the chip to curl.
Coined by Bradley Teets April 1987 in the article "Chip Control On Cutoff Tools" American Machinist Magazine