DIN 2093 — Disc Springs: Calculation & Dimensions
DIN 2093Core design standard for disc springs. Defines geometry (De, Di, t, h₀, L₀), force calculation (F-DIN2093-001), stress analysis, fatigue life assessment, and stacking design (series/parallel/combined). Covers Group 1-3 full size range, OD 8.0-250 mm, thickness 0.2-14 mm, materials 51CrV4/CK67/C75S/H13. DIN 2093 is the parent standard for all subsequent disc spring standards.
Clause Summaries
Scope and Purpose
This standard applies to the design, calculation and inspection of single disc springs. Covers cold-formed and hot-formed disc springs OD 8-250mm.
Terms and Definitions
Defines key geometry: outer diameter De, inner diameter Di, thickness t, free height L₀, cone height h₀=L₀-t. Spring rate correlates positively with h₀/t ratio.
Dimension Series & Groups
Group 1 (thin h₀/t≈0.4), Group 2 (standard h₀/t≈0.75), Group 3 (thick h₀/t≈1.3). Each OD has A/B/C series (different thicknesses).
Force Calculation Formula
Using Almen-Laszlo formula with dimensionless coefficients K₄, K₁ dependent on diameter ratio δ=De/Di. Elastic modulus E and Poisson ratio μ are material-dependent.
Stress Analysis & Strength Verification
Four critical stress points: OM (upper surface inner edge), I (lower inner edge), II (lower mid-ring), III (upper outer edge). Fatigue verification focuses on tensile stress amplitude at OM and II.
Fatigue Life Assessment
Provides stress-life curves for 10⁵ and 2×10⁶ cycles. Fatigue life inversely proportional to stress amplitude, positively correlated with material hardness. Shot peening and presetting improve fatigue life 30-50%.
Stacking Design Guide
Series (n same-direction): deflection×n, force unchanged. Parallel (n alternating): force×n, deflection unchanged. Combined: increases both. Inter-disc friction (μ≈0.02-0.05) causes ±2-5% force deviation.
Material & Heat Treatment
Recommended materials: 51CrV4 (alloy steel, HRC 42-52), CK67/C75S (carbon steel, HRC 40-48). Quench+temper, grain size ≥7, surface decarburization ≤0.01t.
Dimension Table
| de | di | force | group | h0 | t | weight_per_1000 |
|---|---|---|---|---|---|---|
| 8 | 4.2 | 48 | 1A | 0.2 | 0.3 | 0.074 |
| 10 | 5.2 | 98 | 1A | 0.25 | 0.4 | 0.145 |
| 12.5 | 6.2 | 152 | 1A | 0.3 | 0.5 | 0.295 |
| 14 | 7.2 | 175 | 1A | 0.35 | 0.5 | 0.36 |
| 16 | 8.2 | 248 | 1A | 0.4 | 0.6 | 0.55 |
| 18 | 9.2 | 330 | 1B | 0.45 | 0.7 | 0.82 |
| 20 | 10.2 | 425 | 1B | 0.5 | 0.8 | 1.15 |
| 25 | 12.2 | 520 | 2A | 0.7 | 0.9 | 1.95 |
| 31.5 | 16.3 | 920 | 2A | 0.9 | 1.25 | 4.15 |
| 40 | 20.4 | 1480 | 2A | 1.15 | 1.5 | 7.95 |
| 50 | 25.4 | 2650 | 2B | 1.4 | 2 | 16.5 |
| 63 | 31 | 4300 | 2B | 1.75 | 2.5 | 33 |
| 80 | 41 | 7500 | 3A | 2.8 | 3.5 | 72 |
| 100 | 51 | 12500 | 3A | 3.5 | 4.3 | 143 |
| 125 | 64 | 19800 | 3B | 4.5 | 5 | 275 |