BS 4395
Dimensions of Metric Flat Round Washers for High Strength Frict Grip Bolts
| Nom Size | ø D1 | ø D1 | T | |||
|---|---|---|---|---|---|---|
| Max | Min | Max | Min | Max | Min | |
| M12 | 13.8 | 13.4 | 30.0 | 29.0 | 2.8 | 2.4 |
| M16 | 17.8 | 17.4 | 37.0 | 36.0 | 3.4 | 3.0 |
| M20 | 21.5 | 21.1 | 44.0 | 43.0 | 3.7 | 3.3 |
| M22 | 23.4 | 23.0 | 50.0 | 48.5 | 4.2 | 3.8 |
| M24 | 26.4 | 26.0 | 56.0 | 54.5 | 4.2 | 3.8 |
| M27 | 29.4 | 29.0 | 60.0 | 58.5 | 4.2 | 3.8 |
| M30 | 32.8 | 32.4 | 66.0 | 64.5 | 4.2 | 3.8 |
| M33 | 35.8 | 35.4 | 75.0 | 73.5 | 4.6 | 4.2 |
| M36 | 38.8 | 38.4 | 85.0 | 83.5 | 4.6 | 4.2 |
Metric Square Taper Washers for High Strength Frict Grip Bolts
| Nom Size | T | ø D | A, Nom | ||
|---|---|---|---|---|---|
| 3° & 5° Taper, Nom | 8° Taper, Nom | Max | Min | ||
| M12 | 4.76 | 6.35 | 14.2 | 13.4 | 31.75 |
| M16 | 4.76 | 6.35 | 18.2 | 17.4 | 38.10 |
| M20 | 4.76 | 6.35 | 21.9 | 21.1 | 38.10 |
| M22 | 4.76 | 6.35 | 23.8 | 23.0 | 44.45 |
| M24 | 4.76 | 6.35 | 26.8 | 26.0 | 57.15 |
| M27 | 4.76 | 6.35 | 29.8 | 29.0 | 57.15 |
| M30 | 4.76 | 6.35 | 33.2 | 32.4 | 57.15 |
| M33 | 4.76 | 6.35 | 36.2 | 35.4 | 57.15 |
| M36 | 4.76 | 6.35 | 39.2 | 38.4 | 57.15 |
Notes
- Sizes shown in brackets are non prefered
- Sizes M16 to M30 inclusive are common to BS4395 parts 1 and 2. Sizes M12 and M36 are to part 1 only. Size M33 is to Part 2 only.