CST has an extremely broad range of furnaces for both job shop and production carburizing, hardening, and carbonitriding. This includes six integral quench units, two being large 48x72x36 in. furnaces capable of handling 5000 pound payloads. One of these two is set up with hot oil for reducing quench induced distortion. And, for shaft type parts we have two pit furnaces, the deepest capable of running 124 in. long parts.

The key to quality carburizing is atmosphere composition and temperature control. We accomplish this with a computerized system employing an infra-red three gas analyzer and insitu oxygen probes for each furnace. This enables us to have a totally computerized control system for all critical processing elements.

At CST we routinely carburize small parts with total case depths only 0.020 to 0.025in. deep as well as large components requiring effective case depths of 0.250in. and more.

NOTE: When specifying case depth be sure to state whether the amount required is the effective, ie. the depth to 50 HRC, or the total and include allowance for grind stock removal.

While the carburizing process can be used to case harden most low carbon steels, plain carbon grades such as 1010, 1020, A36, etc. should be avoided due to their poor response to oil quenching. For critical components an alloy carburizing grade such as 8620 should be used. On smaller parts the plain carbon grade 1018 will usually oil harden satisfactorily.

For small screw machine parts and stampings where only a hard wear resistant surface is required, carbonitriding is typically specified. This produces a file hard surface with case depths from 0.005 to 0.035in. deep.

If areas on the part are to remain soft a stop off paint or copper plating can be applied. Make sure these areas are clearly noted on the part print.