DIN 440:2024 Wood Construction Square Hole Washer is used in bolted joints for wooden beams, posts, and structural timber connections. The square hole can mate with square-neck bolts or special fasteners to help prevent rotation while providing a larger bearing area.
This washer is suitable for timber buildings, bridge decking components, landscape facilities, wooden supports, and heavy timber assemblies. Compared with a small-diameter washer, the square or enlarged bearing surface reduces the risk of crushing wood fibers and improves joint stability.
Different sizes and coatings can be selected according to timber thickness, bolt specification, and outdoor corrosion requirements, supporting structural fixing, repair reinforcement, and long-term exposed service.

Dimensions unit: mm
|
Applicable thread |
M5 |
M6 |
M8 |
M10 |
M12 |
M16 |
M20 |
M22 |
||
|
a |
Min.=Nominal |
5.5 |
6.6 |
9 |
11 |
14 |
18 |
22 |
24 |
|
|
Max. |
5.8 |
6.96 |
9.36 |
11.43 |
14.43 |
18.7 |
22.84 |
24.84 |
||
|
dc |
Max.=Nominal |
18 |
22 |
28 |
34 |
44 |
56 |
72 |
80 |
|
|
Min. |
16.9 |
20.7 |
26.7 |
32.4 |
42.4 |
54.1 |
70.1 |
78.1 |
||
|
h |
Nominal |
2 |
2 |
3 |
3 |
4 |
5 |
6 |
6 |
|
|
Max. |
2.3 |
2.3 |
3.6 |
3.6 |
4.6 |
6 |
7 |
7 |
||
|
Min. |
1.7 |
1.7 |
2.4 |
2.4 |
3.4 |
4 |
5 |
5 |
||
|
Weight per thousand pieces (steel)≈kg |
3.52 |
5.28 |
12.6 |
18.5 |
41.6 |
84 |
169 |
210 |
||
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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