Home Shop Machining/Equipment/Cutting Materials

Cutting Materials Commonly Used in Home Shop Machining

There are 3 basic materials used for actually cutting material in a home shop:

High Carbon Steel

Steel that can be hardened and tempered. Once hardened, they can be made sharper than the other options but if they are worked too hard then they will heat up and soften. Once this happens, they must be hardened and tempered again before they are useful. Classes of high-carbon steel include:

• Drill Rod
• A2 etc.. steels commonly used in woodworking

Files are typically high carbon steel. These days, the primary use for high carbon steel in home shop machining is the fabrication of custom cutters. Material can be machined into the desired shape and then go through the hardening and tempering process. With care, these cutters can give useful results.

High Speed Steel

Steel specially formulated and heat treated such that it can be heated up to red heat and once cooled down will still retain its hardness. Bought as blanks and then ground to shape, these are very useful in home shop machining, both in lathe work as well as flycutting on a mill. High Speed Steel (HSS) is also used in most commercially available drills and endmills. Heat treating HSS is an exacting process generally beyond home shop capabilities and, as such, it can't be softened (annealed), shaped, and then re-hardened. It can, however, be ground.

Carbide

A very hard class of composite materials. They can be very hard, very hard wearing, but can also be brittle. It generally comes in 2 forms:

• Brazed - where a piece of carbide is brazed to a tool blank and then sharpened.
• Inserts - where the carbide is formed as a replaceable insert that goes into a holder. These inserts often have multiple cutting edges that can be rotated through, and are thus called 'indexible' inserts.

Carbide cannot generally be softened or hardened but can be ground. On a bench grinder, a green wheel is typically used.