ASME B18.13:2017 Hex Head Spring Washer Assembly combines a hex head tapping screw combined with a spring washer in SEMS form and is suitable for engineering joints requiring higher installation torque, tapping efficiency, and auxiliary anti-loosening support.
The pre-assembled spring washer reduces loose-part management and provides elastic compensation, while the hex head suits socket tools and the tapping thread improves field installation efficiency. Compared with ordinary fasteners, this form places more emphasis on controllable installation, surface protection, and efficient management of matching parts for engineering projects requiring stable supply.
It is commonly used in metal brackets, equipment housings, machinery accessories, vehicle components, and repair assemblies. According to drawings or service conditions, spring washer type, surface finish, and material strength can be selected to improve overall fastening performance and service life.

Dimensions unit: inch
|
Thread size d |
4# |
5# |
6# |
7# |
8# |
10# |
12# |
1/4 |
5/16 |
3/8 |
7/16 |
1/2 |
|
|
d1 |
Max. |
0.101 |
0.112 |
0.121 |
0.135 |
0.144 |
0.162 |
0.188 |
0.217 |
0.278 |
0.338 |
0.397 |
0.46 |
|
Min. |
0.096 |
0.107 |
0.116 |
0.13 |
0.138 |
0.156 |
0.181 |
0.209 |
0.27 |
0.33 |
0.388 |
0.451 |
|
|
h |
Min. |
0.025 |
0.031 |
0.031 |
0.031 |
0.04 |
0.047 |
0.056 |
0.062 |
0.078 |
0.094 |
0.109 |
0.125 |
|
dc |
Max. |
0.187 |
0.214 |
0.223 |
0.237 |
0.262 |
0.294 |
0.336 |
0.443 |
0.536 |
0.628 |
0.717 |
0.812 |
|
Min. |
0.176 |
0.201 |
0.21 |
0.224 |
0.248 |
0.28 |
0.321 |
0.427 |
0.52 |
0.612 |
0.7 |
0.793 |
|
|
s |
Max. |
0.188 |
0.188 |
0.25 |
0.25 |
0.25 |
0.312 |
0.312 |
0.375 |
0.5 |
0.562 |
0.625 |
0.75 |
|
Min. |
0.181 |
0.181 |
0.244 |
0.244 |
0.244 |
0.305 |
0.305 |
0.367 |
0.489 |
0.551 |
0.61 |
0.735 |
|
|
k |
Max. |
0.06 |
0.07 |
0.093 |
0.093 |
0.11 |
0.12 |
0.155 |
0.19 |
0.23 |
0.295 |
0.348 |
0.4 |
|
Min. |
0.049 |
0.058 |
0.08 |
0.08 |
0.096 |
0.105 |
0.139 |
0.172 |
0.208 |
0.27 |
0.321 |
0.367 |
|
① The size and type of hexagonal head self-tapping screws refer to ASME B18.6.3.
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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