Overview
ISO 5954:2014 specifies requirements for cold-reduced carbon steel sheet according to hardness requirements. The standard applies to skin-passed or annealed cold-reduced sheet intended for applications where surface quality is a primary concern. Hardness is reported as Rockwell B (HRB) and typical grade designations are CRH-50, CRH-60, CRH-70, and CRH‑NN (user‑agreed ranges).
Key topics and technical requirements
- Hardness ranges (as‑shipped)
- CRH-50: HRB 50–70
- CRH-60: HRB 60–80
- CRH-70: HRB 70–90
- CRH‑NN: any HRB 20‑point range up to HRB 90 (agreed between purchaser and supplier)
- Conversions for thinner product (<1 mm) are given using HR30T in the standard.
- Surface characteristics
- Two surface quality levels: A (unexposed) and B (exposed).
- Surface finish, roughness ranges and suitability for metallic or organic coatings must be agreed at ordering.
- Products are normally oiled for rust protection; unoiled delivery is possible with limited supplier responsibility for oxidation.
- Dimensions and coil sizes
- Produced from nominal 0.36 mm and above (commonly up to 3 mm) and in widths of 600 mm and over (coils and cut lengths).
- Chemical composition and analysis
- Heat analysis limits (examples): Carbon max 0.15% for CRH-50, 0.25% for CRH-60/70/NN; Mn ≤ 0.60%, P ≤ 0.15%, S ≤ 0.03%.
- Limits for additional elements (Cu, Ni, Cr, Mo, Nb, V, Ti) and sum constraints are specified.
- Product analysis tolerances are defined to account for heterogeneity.
- Manufacture and performance
- Hardness control is typically achieved by controlling carbon and/or phosphorus.
- Weldability: normally weldable but becomes more difficult when C > 0.15% or P > 0.05%.
- Skin‑pass influences final hardness and formability; shipped hardness is the acceptance basis.
- Testing, tolerances and inspection
- Rockwell hardness testing per ISO 6508; dimensional/shape tolerances per ISO 16162. Sampling, tests, retests and marking requirements are covered.
Applications and who uses it
- Typical users: steel producers, OEMs, automotive and white‑goods manufacturers, appliance and furniture makers, metal coatings processors, fabricators, and procurement/quality engineers.
- Typical uses: exposed panels, painted or electrolytically coated parts, precision formed components where surface appearance and controlled hardness are critical.
Related standards
- ISO 6508 - Metallic materials - Rockwell hardness test
- ISO 16162 - Cold‑rolled steel sheet products - Dimensional and shape tolerances
- ISO 3574 - (commercial/drawing qualities; note ISO 5954 does not cover these)
ISO 5954:2014 is a practical reference for specifying surface finish, hardness grade (CRH), chemical limits and acceptance criteria when ordering cold‑reduced carbon steel sheet for surface‑sensitive applications.
