Socket Set Screws
Cup, cone, flat, and dog point — plus custom machined options.
Full range of points and lengths, including custom-machined set screws for unique applications.
Specifications & technical data.
Socket set screws to ASME B18.3 — headless, driven by a hex key, holding collars, pulleys and shafts by point pressure. Cup point standard; flat, cone, oval and half-dog to order.
Download our socket set screw dimensioning table (PDF)
| Nominal Size (Basic Screw Diameter) | J | T | C | P | Q | R | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Nominal Hexagon Socket Size | Minimum Key Engagement | Cup & Flat Point Diameter | Half Dog Point Diameter | Half Dog Point Length | Basic Oval Point Radius | ||||||
| Max. | Min. | Max. | Min. | Max. | Min. | ||||||
| #5 | 0.125 | 1/16 | 0.062 | 0.080 | 0.067 | 0.057 | 0.083 | 0.078 | 0.033 | 0.027 | 0.094 |
| #6 | 0.138 | 1/16 | 0.062 | 0.080 | 0.074 | 0.064 | 0.092 | 0.087 | 0.038 | 0.032 | 0.104 |
| #8 | 0.164 | 5/64 | 0.078 | 0.090 | 0.087 | 0.076 | 0.109 | 0.103 | 0.043 | 0.037 | 0.123 |
| #10 | 0.190 | 3/32 | 0.094 | 0.100 | 0.102 | 0.088 | 0.127 | 0.120 | 0.049 | 0.041 | 0.142 |
| 1/4" | 0.250 | 1/8 | 0.125 | 0.125 | 0.132 | 0.118 | 0.156 | 0.149 | 0.067 | 0.059 | 0.188 |
| 5/16" | 0.313 | 5/32 | 0.156 | 0.156 | 0.172 | 0.156 | 0.203 | 0.195 | 0.082 | 0.074 | 0.234 |
| 3/8" | 0.375 | 3/16 | 0.188 | 0.188 | 0.212 | 0.194 | 0.250 | 0.241 | 0.099 | 0.089 | 0.281 |
| 7/16" | 0.438 | 7/32 | 0.219 | 0.219 | 0.252 | 0.232 | 0.297 | 0.287 | 0.114 | 0.104 | 0.328 |
| 1/2" | 0.500 | 1/4 | 0.250 | 0.250 | 0.291 | 0.270 | 0.344 | 0.334 | 0.130 | 0.120 | 0.375 |
| 5/8" | 0.625 | 5/16 | 0.312 | 0.312 | 0.371 | 0.347 | 0.469 | 0.456 | 0.164 | 0.148 | 0.469 |
| 3/4" | 0.750 | 3/8 | 0.375 | 0.375 | 0.450 | 0.425 | 0.562 | 0.549 | 0.196 | 0.180 | 0.562 |
| 7/8" | 0.875 | 1/2 | 0.500 | 0.500 | 0.530 | 0.502 | 0.656 | 0.642 | 0.227 | 0.211 | 0.656 |
| 1" | 1.000 | 9/16 | 0.562 | 0.562 | 0.609 | 0.579 | 0.750 | 0.734 | 0.260 | 0.240 | 0.750 |
| 1-1/8" | 1.125 | 9/16 | 0.562 | 0.562 | 0.689 | 0.655 | 0.844 | 0.826 | 0.291 | 0.271 | 0.844 |
| 1-1/4" | 1.250 | 5/8 | 0.625 | 0.625 | 0.767 | 0.733 | 0.938 | 0.920 | 0.323 | 0.303 | 0.938 |
| 1-3/8" | 1.375 | 5/8 | 0.625 | 0.625 | 0.848 | 0.808 | 1.031 | 1.011 | 0.354 | 0.334 | 1.031 |
| 1-1/2" | 1.500 | 3/4 | 0.750 | 0.750 | 0.926 | 0.886 | 1.125 | 1.105 | 0.385 | 0.365 | 1.125 |
| 1-3/4" | 1.750 | 1 | 1.000 | 1.000 | 1.086 | 1.039 | 1.312 | 1.289 | 0.448 | 0.428 | 1.312 |
| 2" | 2.000 | 1 | 1.000 | 1.000 | 1.244 | 1.193 | 1.500 | 1.474 | 0.510 | 0.490 | 1.500 |
All dimensions in inches, per ASME B18.3-2012. Cup point is standard; flat, cone, oval and half-dog points to order. Chamfer and point-angle rules per the standard. Confirm requirements with our estimating team.
Standards.
What are socket set screws?
A set screw is headless — thread from end to end, a hex socket in one end, and a working point on the other. Sunk flush in a collar or hub, the point bears on the shaft and holds position by friction or indentation.
- Headless — installs flush or below the surface
- Five standard points: cup, flat, oval, cone, half-dog
- Cup point is the general-purpose standard
- Alloy (knurled optional) and stainless
Choosing the point
Cup bites for general holding. Flat protects a surface it bears on. Cone locates in a drilled spot for maximum holding. Oval allows frequent adjustment against a groove. Half-dog fits a mating hole and locates positively.
Other names
- Grub screws
- Allen set screws
- Headless set screws
- Blind screws
Tips for purchasing
- Name the point — cup is assumed if you don't.
- Knurled cup points resist vibration loosening.
- Soft shafts prefer flat or oval points — cup and cone mark the shaft.
- Certs and traceability on request.
Materials.
Representative capabilities — every item is manufactured or certified to your specification. Confirm requirements with our estimating team.
