Engineering chromium is specified for function
ISO 6158:2018 covers electrodeposited chromium for engineering purposes. ASTM B650-23 also describes engineering or functional hard chromium and classifies coatings by thickness. Both point to definable and inspectable requirements.
These references explain communication items; Yixin products do not automatically claim conformity. Adopt a standard or selected clauses only through the confirmed order.
Separate substrate, coating and final size
Confirm substrate material, heat treatment and hardened condition, then pre-plate processing, chromium thickness, post-plate grinding/honing and final size tolerance. Final diameter without coating thickness misses function; thickness without final size can compromise assembly.
An induction-hardened chrome shaft, a non-induction-hardened soft shaft and a Q&T chrome-plated bar are different routes even when all look bright silver.
Select inspection by risk
Typical discussion items include appearance, thickness, hardness, adhesion, porosity and post-treatment, but every order need not use the same set. ASTM B650 lists multiple inspection categories; select them from application, drawing and quality risk.
Define thickness/hardness location, method and sampling. Curvature, transitions and masking can affect readings; one point should not represent a whole shaft without agreement.
Avoid three common assumptions
Do not assume that “hard chrome” means the substrate is induction hardened; that brightness proves thickness or hardness; or that words such as wear/corrosion resistance create an unconditional service-life promise. Confirm substrate, coating, finishing and acceptance against the application.