UNI 1751 B – Spring Lock Washers, Form B
UNI 1751 B is the square-edge form of the split spring lock washer. The drawing shows its open ring and section dimensions.
Selected dimensional schedule (mm)
| For thread | d1 | d2 | s | h | Approx. mass (kg/1000) |
|---|---|---|---|---|---|
| M3 | 3.1 | 6.2 | 0.8 | 1.6 | 0.11 |
| M4 | 4.1 | 7.6 | 0.9 | 1.8 | 0.18 |
| M5 | 5.1 | 9.2 | 1.2 | 2.4 | 0.36 |
| M6 | 6.1 | 11.8 | 1.6 | 3.2 | 0.83 |
| M7 | 7.1 | 12.8 | 1.6 | 3.2 | 0.93 |
| M8 | 8.1 | 14.8 | 2.0 | 4.0 | 1.60 |
| M10 | 10.2 | 18.1 | 2.2 | 4.4 | 2.53 |
| M12 | 12.2 | 21.1 | 2.5 | 5.0 | 3.82 |
| M14 | 14.2 | 24.1 | 3.0 | 6.0 | 6.01 |
| M16 | 16.2 | 27.4 | 3.5 | 7.0 | 8.91 |
| M18 | 18.2 | 29.4 | 3.5 | 7.0 | 9.73 |
| M20 | 20.2 | 33.6 | 4.0 | 8.0 | 15.2 |
| M22 | 22.2 | 35.9 | 4.0 | 8.0 | 16.5 |
| M24 | 24.5 | 40.0 | 5.0 | 10.0 | 26.2 |
| M26 | 26.5 | 43.0 | 5.0 | 11.0 | 27.9 |
| M27 | 27.5 | 44.0 | 5.0 | 11.0 | 28.7 |
| M28 | 28.5 | 45.0 | 5.0 | 11.0 | 29.5 |
| M30 | 30.5 | 49.0 | 6.0 | 13.6 | 44.3 |
Dimensions are in millimetres. This is a selected commercial schedule for square-edge spring lock washers; verify the governing UNI edition where full tolerances are required.
Reference schedule: Spring-washer catalogue (square-edge form).