Overview
ISO 19690-1:2017 - Disc springs - Part 1: Calculation specifies design criteria, definitions and calculation methods for disc springs used singly or in stacks. The standard provides the required design formulae, symbols and units, guidance on dimensions and designation, and methods to evaluate fatigue life, spring load, stress and energy capacity. It is intended for engineers and manufacturers performing mechanical design and verification of disc-spring elements.
Key topics and technical requirements
- Scope and applicability: Formulae apply to typical geometries where 16 < D/t < 40 and 1.8 < D/d < 2.5; consult manufacturers for unusual designs or materials.
- Terms, symbols and units: Conforms to ISO 26909 (vocabulary) and ISO 16249 (symbols).
- Dimensions and groups: Defines disc spring groups by thickness and the use of flat bearings (groups 1–3) and provides dimensional series (A, B, C).
- Design formulae (Clause 6): Includes test-load definition, coefficients, spring load calculations, design stresses at key positions (OM, I–IV), spring rate (non‑linear), and energy capacity integrals.
- Coefficients and corrections: Formulas for C, k and other coefficients, including special treatment when flat bearings or chamfer radius are present.
- Load characteristics: Non‑linear load/deflection behaviour for single springs as a function of h/t and modified curves for springs with flat bearings. Guidance on actual vs. design curves (noting deviations when s/h > 0.75).
- Stacking rules: Behavior and calculation for springs stacked in series, parallel, and mixed arrangements; guidance on guides (inner/outer) and necessary clearances.
- Fatigue and loading types: Coverage of static, moderate fatigue and dynamic loading conditions and how to account for fatigue life in design.
Applications and users
ISO 19690-1:2017 is used by:
- Mechanical and design engineers calculating disc-spring loads, stresses and spring rate
- Spring manufacturers and component suppliers for specification and quality control
- Systems engineers and safety assessors in industries using disc springs (valves, clutches, actuators, vibration isolation, power transmission) who need validated calculation methods and fatigue guidance
- Procurement and standards teams referencing consistent dimensional series and designation
Practical benefits include consistent disc spring design, reliable estimation of fatigue life, predictable stack behavior, and improved component interchangeability.
Related standards
Keywords: ISO 19690-1:2017, disc springs, calculation, design formulae, spring rate, load/deflection, fatigue life, stacking, disc spring design.