C80U · Tool steel

• Cast analysis, mass fraction %. A dash means the standard gives no separate requirement; it does not mean zero.
• Unlisted elements shall not be intentionally added without purchaser consent, except additions needed to finish steelmaking.
• Permissible product-analysis deviations do not expand the default cast-analysis limits.
• Tool-steel classification and hardness depend on application, heat treatment and test conditions; they do not establish cold-heading suitability or guarantee properties in an arbitrary condition.
• Table 2: non-alloy cold-work tool steels; cast analysis, wt%; P and S each ≤.030%.
• Unlisted elements shall not be intentionally added without purchaser consent, except to finish steelmaking. Unspecified Cr, Ni and other elements are not entered as zero.
• The term cold-work tool steel does not establish cold-heading suitability. The product and forming application require separate assessment.
• Note c: C70U to C120U are shallow-hardening steels. A diameter of 30 mm gives a hardened depth of approximately 3 mm; through-hardening may be possible only up to 10 mm diameter. This is not a guarantee for arbitrary dimensions.
• C70U–C120U are shallow-hardening steels: at 30 mm diameter, hardened depth is approximately 3 mm; through-hardening may be possible only at diameters not exceeding 10 mm.
• Annealed and cold-drawn (+A+C) hardness may be 20 HBW higher than annealed (+A) hardness. Hardness values for different conditions must not be interchanged.

Reference: BS EN ISO 4957:2018，Table 2 and notes a/b/c. Website information does not replace the official standard, order specifications or material certificates.