What is the correct ways for hardening gears & cutting tools ? thanks?

Question

we make spareparts for our factory and always face problems in hardening methods ,

Answer 1

quelching

Answer 2

The process of hardening metal parts is not too complicated, but it takes a bit of experience to get it 100% right. Basically, you need to heat the parts up to a glowing red hot evenly across the entire part. Then, depending on the size of the part, you immerse the part in cold water, or in some cases oil. Oil is used for bigger parts, I believe. When the part is cooled rapidly, the molecules in the part align themselves in a different manner than if they were to cool slowly. Hardened parts are just that, harder, but they are a lot more brittle than parts not heat treated.

Hope this helps.....