ISO 11891:2012

Hot formed helical compression springs — Technical specifications

Scope

This International Standard specifies the materials, shapes, spring characteristics, tolerances, manufacturing
requirements and test methods for common helical compression springs, which are made from hot coiled
round section steel bar, and then quenched and tempered (hereinafter simply "springs").
The following limit values apply to springs conforming to this International Standard:
— free length: ≤ 900 mm;
— spring index: 3 to 12;
— slenderness ratio: 0,8 to 4;
— active coils: ≥ 3;
— spring pitch: < 0,5D;
— wire diameter: 8 mm to 60 mm;
— mean diameter of coil: ≤ 460 mm.
This International Standard is not applicable to coil springs with special performance requirements, such as
railway and automotive suspensions.