ISO 23213:2022

Overview

ISO 23213:2022 - Carbon steel wire for bedding and seating springs - specifies requirements for cold-drawn, round carbon steel wire supplied in the uncoated condition for manufacture of springs used in bedding and seating in the automotive and furniture industries. The standard defines classification, dimensional and mechanical requirements, testing, inspection, packing and marking to ensure consistent spring performance and interchangeability.

Key Topics and Requirements

• Scope & classification
  • Applicable nominal diameters: 0.80 mm to 6.00 mm.
  • Five wire types (I–V) for different spring applications (e.g., pocket, Bonnell, link, edging, sinuous) with recommended diameter ranges.
• Diameter, tolerance & geometry
  • Diameter measured as mean of two orthogonal micrometer readings; specified tolerances vary by diameter range (examples provided in the standard).
  • Ovality limits, wire cast (circular and helix cast) and tip rise requirements are specified.
• Mechanical properties
  • Tensile strength requirements given by type and diameter (detailed ranges for Types I–V).
  • Maximum tensile range variation within a batch: 150 MPa.
• Forming tests
  • Wrapping test (ISO 7802) for wire < 4.0 mm - wire must not fracture when close wrapped three turns around a mandrel equal to the wire diameter.
  • Torsion test (ISO 7800) for Types I–III with specified torsion values.
  • Tensile testing per ISO 6892-1.
• Surface and manufacturing
  • Surface must be smooth and free from defects that adversely affect use; welds after cold drawing are not permitted.
  • Minimum coil weights and single-heat coil requirements are defined.
• Inspection & sampling
  • Routine inspection items per coil (diameter, surface, cast, tip rise) and sample-based tests for tensile, wrapping and torsion (typically 10% of coils, at least 3).
  • Batching rules, retest and acceptance criteria provided.
• Marking & purchaser information
  • Example marking: “φ2,80 mm - Type II - ISO 23213:2022”.
  • Purchaser must specify classification, nominal diameter, tensile grade, anti-rust treatment, quantity, unit mass, etc.

Applications and Users

• Intended for spring manufacturers, wire producers, OEMs in automotive seating and furniture (mattresses, seat frames, sinuous springs, pocket springs).
• Useful for procurement, quality control, product design and compliance teams specifying uncoated carbon spring wire for bedding and seating applications.

Related Standards (normative references)

• ISO 6892-1 - Tensile testing of metallic materials
• ISO 7800 - Wire torsion test
• ISO 7802 - Wire wrapping test
• ISO 16120-1 / ISO 16120-2 - Non-alloy steel wire rod requirements

Keywords: ISO 23213:2022, carbon steel wire, bedding and seating springs, spring wire, tensile strength, wrapping test, torsion test, diameter tolerance, uncoated wire, automotive, furniture.