DIN 6796 — Conical Spring Washers
DIN 6796Conical spring washer standard, providing sustained elastic preload compensation for bolted joints. Heat treatment and presetting of conical shape yield stable elastic characteristics. Prevents preload loss from thermal expansion, creep, and settlement. Lower h₀/t ratio than DIN 2093; spring rate near-linear. Typical applications: transformer/motor/heat exchanger joints under thermal cycling.
Clause Summaries
Scope & Design
Covers M3-M36 bolt sizes. Cone angle 6°-8°, materials C67S/C75S/51CrV4. Design preload compensation range 10-25% of initial bolt preload. Operating temperature -30°C~+200°C.
Elastic Characteristics
DIN 6796 washer force-deflection is near-linear (h₀/t=0.28-0.35), force tolerance ±10% (Grade A)/±15% (Grade B). After presetting, spring characteristics stable; relaxation <3%/10⁴ cycles.
Dimension Table
| de | di | force | group | h0 | t | weight_per_1000 |
|---|---|---|---|---|---|---|
| 6.2 | 3.1 | 250 | 3.0 | 0.15 | 0.5 | 0.058 |
| 7.6 | 4.1 | 420 | 4.0 | 0.2 | 0.6 | 0.105 |
| 9.2 | 5.1 | 680 | 5.0 | 0.25 | 0.8 | 0.2 |
| 11 | 6.1 | 1100 | 6.0 | 0.3 | 1 | 0.35 |
| 15 | 8.1 | 2100 | 8.0 | 0.4 | 1.4 | 0.9 |
| 18 | 10.2 | 3200 | 10.0 | 0.5 | 1.7 | 1.6 |
| 21 | 12.2 | 4900 | 12.0 | 0.6 | 2.1 | 2.7 |
| 28 | 16.2 | 9200 | 16.0 | 0.8 | 2.8 | 6.4 |