DIN 6331:1991 Nut with integrated bearing surface provides washer-like support during assembly. Its design helps distribute load, improve contact stability, and reduce the need for a separate washer in selected applications.
This product is suitable for fixtures, tooling, machine-tool accessories, metal brackets, and equipment connections, especially where frequent removal or a more stable bearing face is required. The hex exterior allows operation with standard tools and improves installation efficiency on site.
Strength class, material, and surface finish options can be selected according to service conditions to meet requirements for wear resistance, corrosion protection, and repeated assembly.

Dimensions unit: mm
| Thread size | M6 | M8 | M10 | M12 | M16 | M20 | M24 | M27 | M30 | M36 | M42 | M48 | ||
| d | ||||||||||||||
| P | Pitch | 1 | 1.25 | 1.5 | 1.75 | 2 | 2.5 | 3 | 3 | 3.5 | 4 | 4.5 | 5 | |
| a | Nominal | 3 | 3.5 | 4 | 4 | 5 | 6 | 6 | 7 | 8 | 10 | 12 | 14 | |
| Max. | 3.125 | 3.65 | 4.15 | 4.15 | 5.15 | 6.15 | 6.15 | 7.18 | 8.18 | 10.18 | 12.215 | 14.215 | ||
| Min. | 2.875 | 3.35 | 3.85 | 3.85 | 4.85 | 5.85 | 5.85 | 6.82 | 7.82 | 9.82 | 11.785 | 13.785 | ||
| d1 | Max. | 14 | 18 | 22 | 25 | 31 | 37 | 45 | 50 | 58 | 68 | 80 | 92 | |
| Min. | 13.73 | 17.73 | 21.67 | 24.67 | 30.61 | 36.61 | 44.61 | 49.61 | 57.54 | 67.54 | 79.54 | 91.46 | ||
| da | Min. | 6 | 8 | 10 | 12 | 16 | 20 | 24 | 27 | 30 | 36 | 42 | 48 | |
| Max. | 6.75 | 8.75 | 10.8 | 13 | 17.3 | 21.6 | 25.9 | 29.1 | 32.4 | 38.9 | 45.4 | 51.8 | ||
| e | Min. | 11.05 | 14.38 | 17.77 | 20.03 | 26.75 | 33.53 | 39.98 | 45.63 | 51.28 | 61.31 | 72.61 | 53.91 | |
| m | Nominal | 9 | 12 | 15 | 18 | 24 | 30 | 36 | 40 | 45 | 54 | 63 | 72 | |
| Max. | 9.29 | 12.35 | 15.35 | 18.35 | 24.42 | 30.42 | 36.5 | 40.5 | 45.5 | 54.6 | 63.6 | 72.6 | ||
| Min. | 8.71 | 11.65 | 14.65 | 17.65 | 23.58 | 29.58 | 35.5 | 39.5 | 44.5 | 53.4 | 62.4 | 71.4 | ||
| s | Max. | 10 | 13 | 16 | 18 | 24 | 30 | 36 | 41 | 46 | 55 | 65 | 75 | |
| Min. | 9.78 | 12.73 | 15.73 | 17.73 | 23.67 | 29.67 | 35.38 | 40.38 | 45.38 | 54.26 | 64.26 | 74.26 | ||
| r | Max. | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | |
| Weight per thousand pieces (steel)≈kg | 5 | 12.4 | 25.5 | 36.5 | 71 | 135 | 230 | 320 | 470 | 810 | 1340 | 2040 | ||
ABOUT US
Better Fastener is a professional fastener enterprise specializing in the manufacturing of steel washers, stainless steel washers, spring washers and sealingwashers. Founded in 2001 as a washer factory, the company expanded into a comprehensive enterprise integrating washers, nuts, bolts, spring nuts and other fastener products in 2010.
The company positions itself as a provider of comprehensive one-stop services for customers, relying on technological R&D, industrial investment and trade distribution.
With an experienced professional team and a sound sales network, Better Fastener has achieved excellent sales performance in both domestic and foreign markets,and has grown into one of the competitive manufacturers and suppliers in China's industrial fastener industry.
Better Fastener is committed to becoming a trusted fastener supplier for customers with reliable product quality, reasonable prices and on-time delivery
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