ISO 18137:2015 PDF

Overview

ISO 18137:2015 - Leaf springs - Technical specifications defines the technical requirements and tolerances for leaf springs used mainly in road vehicles. The standard covers materials, dimensional and shape tolerances, characteristic requirements (spring rate, camber, fatigue), and manufacturing controls (hardness, decarburization, shot peening, presetting, lubrication, surface protection). It also includes illustrations of common spring types (multi‑leaf, parabolic, sliding ends, progressive designs) and refers to Annex A for test methods.

Key topics and technical requirements

• Scope and applicability: Applies to leaf springs for road vehicles; other vehicle types may refer to it.
• Materials: Preferably hot‑rolled spring flat bar in accordance with ISO 683‑14 unless otherwise agreed.
• Dimensional tolerances:
  • Straight span and fixed half straight span tolerances are specified by range and type (examples: ±3.0 mm to ±6.5 mm depending on span and Type 1/Type 2).
  • Assembled spring width and eye widths have defined tolerances (assembly width tolerance examples: +2.5/−0.8 mm up to specific widths).
  • Eye inner diameter tolerances (e.g., ±0.5 mm for d ≤ 25 mm; ±0.6 mm for 25