1040 – 07 – Adding New Material to Metal

1m

A metal’s make up isn’t uniform at all times. Usually, metal has variations in its composition – variations that will still be in the metal after the cutting process. Oftentimes, particles, called inclusions, within the metal are unwanted. They can have a negative effect on the metal’s machinability.

Not all inclusions are harder than the metal that surrounds it. Manufacturers will oftentimes use additives in a metal to improve machinability.

Free-machining steels have additives that make it easier to machine. Often, these additives include sulfur, lead, and bismuth, which act as lubricants. Sulfur also helps chips break appropriately.