ASME/ANSI B18.3 Hexagon Socket Head Cap Screws
ASME/ANSI B18.3 Hexagon Socket Head Cap Screws feature a cylindrical head with a recessed hexagon socket, providing a compact fastening solution where conventional external-head bolts may require more installation space. The internal hex drive allows the screw to be tightened from above with an Allen-type wrench, making it suitable for assemblies where access around the fastener head is limited.
The socket head design provides a relatively small head diameter while maintaining a substantial bearing area and robust head section. This makes Socket Head Cap Screws well suited to machine components, tooling, fixtures, equipment assemblies, and other compact mechanical connections where strength and space efficiency are important. For selection, customers should consider the nominal diameter, screw length, thread series, material, strength grade, hardness, surface finish, and available tool access to ensure the screw matches both the joint requirements and installation conditions.
Specification:
| Item | Specification |
|---|---|
| Standard | ASME/ANSI B18.3 |
| Product Type | Hexagon Socket Head Cap Screw |
| Head Style | Cylindrical Head |
| Drive Type | Hexagon Socket/Internal Hex |
| Thread System | Inch |
| Thread Series | UNC/UNF |
| Size Range | #0-1/2" |
| Material | Alloy Steel, Stainless Steel |
| Alloy Steel Standard | SAE J429 |
| Stainless Steel Standard | ASTM F593 |
| Surface Treatment | Plain,Zinc Plated,Black Oxidation,Bright Finish,Passivation |
- RELATED SCREW LISTS:
- Hexagon Socket Cap Screw
- DIN912 Hexagon Socket Cap Screw
- ASME B18.3 Hexagon Socket Cap Screw
- DIN6912 Hexagon Socket Cap Screw
- DIN7984 Low Head Socket Cap Screw
- Hexagon Socket Countersunk Screw
- DIN7991 Hex Socket Countersunk Screw
- ISO10642 Hex Socket Countersunk Screw
- ASME B 18.3F Hexagon Socket Countersunk Screw
Dimension Chart:
| Mon | #0 | #1 | #2 | #3 | #4 | #5 | #6 | #8 | #10 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 | 5/8 | 3/4 |
| P | 80 | 64|72 | 56|64 | 48|56 | 40|48 | 40|44 | 32|40|48 | 32|36 | 24|32 | 20|28|32 | 18|24|32 | 16|24|32 | 14|20|28 | 13|20|28 | 11|18|24 | 10|16|20 |
| dk max | 0.096 | 0.118 | 0.14 | 0.161 | 0.183 | 0.205 | 0.226 | 0.27 | 0.312 | 0.375 | 0.469 | 0.562 | 0.656 | 0.75 | 0.938 | 1.125 |
| dk min | 0.091 | 0.112 | 0.134 | 0.154 | 0.176 | 0.198 | 0.216 | 0.257 | 0.298 | 0.354 | 0.446 | 0.54 | 0.631 | 0.725 | 0.914 | 1.094 |
| k max | 0.06 | 0.073 | 0.086 | 0.099 | 0.112 | 0.125 | 0.138 | 0.164 | 0.19 | 0.25 | 0.312 | 0.375 | 0.438 | 0.5 | 0.625 | 0.75 |
| k min | 0.057 | 0.07 | 0.083 | 0.095 | 0.108 | 0.121 | 0.134 | 0.159 | 0.185 | 0.244 | 0.306 | 0.368 | 0.43 | 0.492 | 0.616 | 0.74 |
| s | 0.05 | 0.062 | 0.078 | 0.078 | 0.094 | 0.094 | 0.109 | 0.141 | 0.156 | 0.188 | 0.25 | 0.312 | 0.375 | 0.375 | 0.5 | 0.625 |
| t min | 0.025 | 0.031 | 0.038 | 0.044 | 0.051 | 0.057 | 0.064 | 0.077 | 0.09 | 0.12 | 0.151 | 0.182 | 0.213 | 0.245 | 0.307 | 0.37 |
Application of ASME/ANSI B18.3 Hexagon Socket Head Cap Screws:
Machine Tools and Fixtures
Socket Head Cap Screws are widely suited to machining fixtures, workholding devices, tooling plates, jigs, and machine-tool components where fasteners need to sit within a compact space and can be accessed from the top with a hex key.
Industrial Equipment
They are commonly used for machine guards, gearbox housings, pump assemblies, conveyor equipment, linear-motion components, and equipment frames. The cylindrical head provides a relatively small footprint while the internal hex drive allows installation where an external wrench would be difficult to position.
Precision Mechanical Assemblies
The compact head and recessed drive make these screws useful for bearing housings, positioning mechanisms, actuator assemblies, guide systems, and adjustable machine components where surrounding parts may limit wrench access.