20Cr Steel: Case-Hardened Parts

20Cr is a chromium-alloy steel designation in the Chinese grade system. Material reference.

Case-Hardened Parts

For a pin or gear requiring a hard surface and a less hard core, separate the case requirement from the stock grade. Do not approve a foreign cross-reference solely because its chromium description looks similar; the product specification and delivered condition also need comparison.

Manufacturing and acceptance checks

Request the governing standard and heat number. Define effective case depth, its hardness threshold, core test position and surfaces that must remain unhardened. Leave a stated allowance for final bore and tooth finishing, and check that the inspection plan measures the case after that finishing.

Compare related options

• 20CrMnTi Steel
• 8620 Steel

Reference and scope

Baosteel: structural and spring steel grade families provides material or specification background. The checks above are purchasing guidance; final acceptance values must come from the agreed grade, product specification and condition.

Send a drawing and material requirements for review. Include quantity, critical dimensions and the inspection evidence required with delivery.