# Conical spring washer (DIN 6796)

Conical spring washer (disc spring) for bolted joints, M2 to M125, with catalogue sizes as presets.

## Geometry

The washer in its free state: hole **d**, outside diameter **d1**, material thickness **s** and free height **h**
(max). The section is a parallelogram with vertical sides: the outer edge rests on the XY plane at the origin and the
inner edge is raised, the washer rising along +Z.

## Parameters

| Parameter | Meaning |
|---|---|
| `size` | Thread size, M2 to M125 |
| `material` | `spring-steel`, `stainless` (martensitic) |

## Source

DIN 6796:2009-08, *Conical spring washers for bolted connections*, dimension table, read from the reproduction on
fasten.it ("reproduced by permission of DIN", <https://fasten.it/norms/norm/din_6796>) (mm). fasteners.eu (<https://www.fasteners.eu/standards/DIN/6796/>, no
edition named) agrees except M7 s (1.75) and M18 h max (5.6); the values below are the 2009 edition's as fasten.it
gives them.

| Size | d | d1 | s | h max |
|---|---|---|---|---|
| M2 | 2.2 | 5 | 0.4 | 0.6 |
| M2.5 | 2.7 | 6 | 0.5 | 0.72 |
| M3 | 3.2 | 7 | 0.6 | 0.85 |
| M3.5 | 3.7 | 8 | 0.8 | 1.06 |
| M4 | 4.3 | 9 | 1 | 1.3 |
| M5 | 5.3 | 11 | 1.2 | 1.55 |
| M6 | 6.4 | 14 | 1.5 | 2 |
| M7 | 7.4 | 17 | 1.8 | 2.3 |
| M8 | 8.4 | 18 | 2 | 2.6 |
| M10 | 10.5 | 23 | 2.5 | 3.2 |
| M12 | 13 | 29 | 3 | 3.95 |
| M14 | 15 | 35 | 3.5 | 4.65 |
| M16 | 17 | 39 | 4 | 5.25 |
| M18 | 19 | 42 | 4.5 | 5.8 |
| M20 | 21 | 45 | 5 | 6.4 |
| M22 | 23 | 49 | 5.5 | 7.05 |
| M24 | 25 | 56 | 6 | 7.75 |
| M27 | 28 | 60 | 6.5 | 8.35 |
| M30 | 31 | 70 | 7 | 9.2 |
| M33 | 34 | 76 | 7.5 | 10 |
| M36 | 37.2 | 83 | 8 | 10.5 |
| M42 | 43.5 | 96 | 8.5 | 12 |
| M48 | 49.5 | 110 | 9 | 12.5 |
| M56 | 58 | 128 | 9.5 | 13.5 |
| M64 | 66 | 136 | 10 | 14 |
| M72 | 74 | 145 | 10.5 | 15 |
| M90 | 92.5 | 160 | 11 | 16 |
| M100 | 102.5 | 180 | 11.5 | 17 |
| M125 | 128 | 220 | 12 | 19 |

Preset list: sizes of the step.parts catalogue (MIT), see `library/NOTICE.md`. The catalogue's generic disc spring washers name no standard; their presets use DIN 6796.