Overview
ISO 3076:2012 specifies requirements for round steel short link sling chains - Grade 8 (medium tolerance) intended for chain slings and general lifting purposes. It covers electrically welded, heat-treated and tested short-link chains in nominal sizes from 4 mm to 45 mm, designed to operate in the temperature range –40 °C to +400 °C. Chains complying with ISO 3076 must also meet the general conditions of acceptance of ISO 1834.
Key topics and technical requirements
- Scope and sizes: Nominal material diameters covered: 4 mm to 45 mm; dimensions, pitch and widths are defined with tolerances.
- Chain types and weld limits: Two link types (Type 1 and Type 2) are defined with maximum permitted weld oversize - typically ≤10% in all directions for Type 1; Type 2 allows ≤10% perpendicular to the plane and ≤25% in other planes to maintain functioning and clearance.
- Material and metallurgy:
- Steel produced by electric or oxygen-blown processes.
- Fully killed steel with controlled sulfur, phosphorus and specified alloying (nickel, chromium, molybdenum where applicable) to ensure toughness and low-temperature ductility.
- Aluminium content required to stabilize against strain-age embrittlement.
- Heat treatment: Hardened from above the Ac point and tempered - tempering at ≥400 °C for 1 hour is required (verification procedures included).
- Mechanical and safety tests:
- Working Load Limits (WLLs), Manufacturing Proof Force (MPF) and Breaking Force (BF) are specified per nominal size (see standard tables).
- Total ultimate elongation minimums (e.g., 20% for natural black finish).
- Bend deflection requirements for individual links and toughness verified by Charpy/impact testing (ISO 148-1, ISO 14556).
- Sampling, lot size and verification procedures for MPF, BF and impact tests are detailed.
- Marking and certification: Grade marking, identification and inspection marking rules and manufacturer’s certificate requirements are included.
Applications and users
ISO 3076 is directly applicable to:
- Chain sling manufacturers and component suppliers for producing Grade 8 sling chains.
- Rigging and lifting equipment designers, procurement/specifiers, and safety engineers who select chains for overhead lifting, hoisting and material handling.
- Inspection and testing laboratories performing mechanical and impact verification.
- Asset owners and fleet managers who require certified chain slings for safe lifting operations.
Practical benefits include consistent WLL determination, assured weld quality, validated low-temperature performance, and traceable marking and certification for compliance and safety.
Related standards
Keywords: ISO 3076, Grade 8 sling chains, short link chains, chain slings, working load limit, manufacturing proof force, breaking force, heat treatment, weld diameter, lifting safety.
Open preview (PDF)Round steel short link chains for general lifting purposes — Medium tolerance sling chains for chain slings — Grade 8
