SUS420: Clarifying J1 and J2

A short SUS420 callout is incomplete when the drawing requires a specific variant such as SUS420J1 or SUS420J2. Material reference.

Clarifying J1 and J2

Before selecting stock for a blade, valve or wear part, resolve the full designation and required finished hardness. Do not average properties from different 420 variants into one material table or assume a supplier's commercial 420 label establishes the intended chemistry.

Manufacturing and acceptance checks

Obtain the original standard and the mill's complete grade designation. Define the heat-treatment condition, edge or sealing geometry and finishing allowance. Approve a first article after the final grinding operation, with hardness and corrosion requirements tied to that finished condition.

Compare related options

• SUS410
• SUS440A

Reference and scope

Daido: JIS stainless grade identities and chemistry 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.