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Carbon Steel Typical Heat Treatments Case Hardening Grade Table Chart

Engineering Materials
Applications & Design

Case hardening processes harden only the exterior of the steel part, creating a hard, wear resistant skin (the "case") but preserving a tough and ductile interior. Carbon steels are not very hardenable ; therefore wide pieces cannot be through-hardened. Alloy steels have a better hardenability, so they can through-harden and do not require case hardening. This property of carbon steel can be beneficial, because it gives the surface good wear characteristics but leaves the core tough.

Case Hardening Grade for Carbon Steel

SAE Steels1	Carbon Temp F	Cooling Method	Reheat Temp F	Cooling Medium	Carbonitriding Temp F2	Cooling Method	Temper F3
1010	-	-	-	-	1450-1650	Oil	250-400
1015	-	-	-	-	1450-1650	Oil	250-400
1016	1650-1700	Water or Caustic	-	-	1450-1650	Oil	250-400
1018	1650-1700	Water or Caustic	1450	Water or Caustic4	1450-1650	Oil	250-400
1019	1650-1700	Water or Caustic	1450	Water or Caustic4	1450-1650	Oil	250-400
1020	1650-1700	Water or Caustic	1450	Water or Caustic4	1450-1650	Oil	250-400
1022	1650-1700	Water or Caustic	1450	Water or Caustic4	1450-1650	Oil	250-400
1026	1650-1700	Water or Caustic	1450	Water or Caustic4	1450-1650	Oil	250-400
1030	1650-1700	Water or Caustic	1450	Water or Caustic4	1450-1650	Oil	250-400
1109	1650-1700	Water or Oil	1400-1450	Water or Caustic4	-	-	250-400
1117	1650-1700	Water or Oil	1450-1600	Water or Caustic4	1450-1650	Oil	250-400
1118	1650-1700	Oil	1450-1600	Oil	-	-	250-400
1513	1650-1700	Oil	1450	Oil	-	-	250-400
1518	-	-	-	-	-	-	-
1522	1650-1700	Oil	1450	Oil	-	-	250-400
1524 (1024)	1650-1700	Oil	1450	Oil	-	-	250-400
1525	1650-1700	Oil	1450	Oil	-	-	250-400
1526	1650-1700	Oil	1450	Oil	-	-	250-400
1527 (1027)	1650-1700	Oil	1450	Oil	-	-	250-400

1. Generally, it is not necessary to normalize the carbon grades for fulfilling either dimensional or machinability requirements of parts made from the steel grades listed in the table, although where dimension is of vital importance normalizing temperatures of at least 50ºF above the carburizing temperatures are sometimes required.
2. The higher manganese steels such as 1118 and the 1500 series are not usually carbonitrided. If carbonitriding is performed, care must be taken to limit the nitrogen content because high nitrogen will increase their tendency to retain austenite.
3. Even where recommended draw temperatures are shown, the draw is not mandatory on many applications. Tempering is generally employed for a partial stress relief and improves resistance to cracking from grinding operations. Higher temperatures than those shown may be employed where the hardness specification on the finished parts permits.
4. 3% sodium hydroxide.

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