ASME/ANSI B18.5 (T1):2012 Inch Series Round Head Bolt uses a smooth round head profile for inch-series joints where exposed-surface safety, touch comfort, and a neat appearance are important.
The rounded head reduces exposed sharp edges and is suitable for wood structures, light metal components, guardrails, furniture-style assemblies, and general decorative fastening. The inch system supports matching with nuts, washers, and hole patterns used in North American or legacy equipment.
When selecting this product, thread series, head diameter, shank length, and surface finish should be confirmed. For exposed or human-contact areas, corrosion-resistant coatings and smooth surface quality are especially useful.

Dimensions unit: inch
|
Thread size d |
10# |
1/4 |
5/16 |
3/8 |
7/16 |
1/2 |
5/8 |
3/4 |
7/8 |
1 |
|
|
d |
0.1900 |
0.2500 |
0.3125 |
0.3750 |
0.4375 |
0.5000 |
0.6250 |
0.7500 |
0.8750 |
1.0000 |
|
|
PP |
24 |
20 |
18 |
16 |
14 |
13 |
11 |
10 |
9 |
8 |
|
|
ds |
Max. |
0.199 |
0.260 |
0.324 |
0.388 |
0.452 |
0.515 |
0.642 |
0.768 |
0.895 |
1.022 |
|
Min. |
0.182 |
0.237 |
0.298 |
0.360 |
0.421 |
0.483 |
0.605 |
0.729 |
0.852 |
0.976 |
|
|
dk |
Max. |
0.469 |
0.594 |
0.719 |
0.844 |
0.969 |
1.094 |
1.344 |
1.594 |
1.844 |
2.094 |
|
Min. |
0.438 |
0.563 |
0.688 |
0.782 |
0.907 |
1.032 |
1.219 |
1.469 |
1.719 |
1.969 |
|
|
k |
Max. |
0.114 |
0.145 |
0.176 |
0.208 |
0.239 |
0.270 |
0.344 |
0.406 |
0.469 |
0.531 |
|
Min. |
0.094 |
0.125 |
0.156 |
0.188 |
0.219 |
0.250 |
0.313 |
0.375 |
0.438 |
0.500 |
|
① Minimum thread length:
The minimum length of the threads shall be equal to twice the basic bolt diameter plus 0.25 inch for nominal bolt lengths of 6 inches or less, and twice the basic bolt diameter plus 0.50 inch for longer nominal lengths.
Bolts whose nominal length is too short to accommodate the minimum thread length shall be fully threaded. The length from the head or neck to the first full (full) thread shall not exceed 2-1/2 threads (sizes 1 inch or less) and 3-1/2 threads (sizes greater than 1 inch).
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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