Bring on the Heat: General Industry Coverage

Contrary to popular belief, the cutting edges of cutting tools don’t actually produce chips. What happens is that the pressure of a rapidly spinning tool on a workpiece plasticizes part of the parent material, creating a shearing effect that forces the material to ride up the tool. The flute and tool geometries form the chip and force it away from the tool body until it breaks off and evacuates.

(Click here to view a video produced by Iscar Metals Inc. that depicts this process.)

Is there something you can take away from this improved understanding to make your CNC machining processes more effective? Indeed, there is.

Constant chip thickness is needed for keeping an optimal amount of heat in the chip and directing it from the tool and workpiece. Image courtesy CNC Software.

One of the biggest takeaways is a heightened appreciation for the roles that machining parameters and heat play when cutting metal. Heat is not always the enemy. Rather, it is an essential ingredient of the cutting process and should be carefully managed to create optimal material-removal conditions.

Advanced cutting tools can take the heat. Toolmakers protect their products with coatings that permeate and encapsulate the tool’s molecules to make them slippery and able to resist degradation due to pressure, friction and high heat levels. This protection is needed because temperatures ranging from 1,000° F to more than 3,000° F (538° C to 1,649° C) are frequently necessary to plasticize the material and achieve the desired metal-removal rate.