ISO 5950:2012

Overview

ISO 5950:2012 specifies requirements for electrolytic tin-coated cold‑reduced carbon steel sheet (coil or cut lengths) of commercial and drawing qualities. The standard covers products produced by electrolytic tin deposition where solderability, appearance, or a degree of corrosion resistance is required and where the coating mass can be specified. Coating mass is expressed as the total tin on both surfaces in grams per square metre (g/m2). ISO 5950:2012 does not apply to tinplate or blackplate.

Key topics and technical requirements

• Product scope and forms: Cold‑reduced carbon steel sheet supplied in coils or cut lengths; commonly skin‑passed prior to tinning. Typical production thickness range noted in the standard is about 0.50 mm to 0.85 mm (market variants exist).
• Coating mass designations: Coatings are designated SN with nominal coating masses such as SN056 (5.6 g/m2), SN112, SN168, SN224 (total both sides). The standard defines nominal, minimum and check limits for coating mass.
• Coating condition: Two main surface conditions - BR (bright, reflowed/fused) and MA (matt, not reflowed) - with reflow producing a bright finish and some iron‑tin alloy formation.
• Material qualities: Quality designations 01 (commercial), 02 (drawing), 03 (deep drawing) and 04 (deep drawing aluminum killed) with associated chemical composition limits (C, Mn, P, S) and fabrication targets.
• Manufacture and testing: Includes requirements for chemical composition reporting, coating mass testing methods, tensile testing of base metal (reference to ISO 6892‑1), dimensional tolerances and sampling procedures.
• Designation system: Combines coating type, coating mass, coating condition and quality (example: SN056BR03 - tin coating, 5.6 g/m2, bright reflowed, deep drawing quality).

Applications and who uses this standard

ISO 5950:2012 is used by:

• Steel producers and tinning mills for specification, production control and product marking of electrolytic tin‑coated sheet.
• Purchasers, fabricators and OEMs who require predictable solderability, aesthetic finishes or limited corrosion resistance for formed parts.
• Quality and inspection teams to verify coating mass, mechanical properties and surface condition during acceptance.

Typical applications include components and assemblies where tin coating improves solderability, surface appearance or service life under defined environmental conditions.

Related standards

• ISO 6892‑1 - tensile testing of metallic materials (room temperature)
• ISO 16162 - cold‑rolled steel sheet dimensional and shape tolerances

Keywords: ISO 5950:2012, electrolytic tin‑coated sheet, tin coating, coating mass, cold‑reduced carbon steel, solderability, SN056.