Socket Head Shoulder Screws
Precision ground shoulders for pivots and bearings.
Shoulder screws (stripper bolts) with ground shanks for rotating and sliding parts.
Specifications & technical data.
Socket head shoulder screws to ASME B18.3 — a precision-ground shoulder that works as a shaft, pivot or bearing seat, with an undersized thread that pulls the shoulder tight against the face.
Download our shoulder screw dimensioning table (PDF)| Nominal Shoulder Diameter | D — Shoulder Diameter | A — Head Diameter | H — Head Height | J — Hexagon Socket Size | T — Min. Key Engagement | Thread Size | E — Basic Thread Length | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Max. | Min. | Max. | Min. | Nom. | Dec. | ||||
| 1/8" | 0.123 | 0.121 | 0.250 | 0.235 | 0.125 | 0.115 | 5/64 | 0.078 | 0.067 | 4-40 | 0.157 |
| 5/32" | 0.154 | 0.152 | 0.281 | 0.266 | 0.125 | 0.115 | 3/32 | 0.094 | 0.067 | 6-32 | 0.187 |
| 3/16" | 0.185 | 0.183 | 0.312 | 0.296 | 0.156 | 0.146 | 3/32 | 0.094 | 0.079 | 8-32 | 0.189 |
| 1/4" | 0.248 | 0.246 | 0.375 | 0.357 | 0.188 | 0.177 | 1/8 | 0.125 | 0.094 | 10-24 | 0.375 |
| 5/16" | 0.311 | 0.309 | 0.438 | 0.419 | 0.219 | 0.209 | 5/32 | 0.156 | 0.117 | 1/4-20 | 0.438 |
| 3/8" | 0.373 | 0.371 | 0.562 | 0.543 | 0.250 | 0.240 | 3/16 | 0.188 | 0.141 | 5/16-18 | 0.500 |
| 1/2" | 0.498 | 0.496 | 0.750 | 0.729 | 0.312 | 0.302 | 1/4 | 0.250 | 0.188 | 3/8-16 | 0.625 |
| 5/8" | 0.623 | 0.621 | 0.875 | 0.853 | 0.375 | 0.365 | 5/16 | 0.312 | 0.234 | 1/2-13 | 0.750 |
| 3/4" | 0.748 | 0.746 | 1.000 | 0.977 | 0.500 | 0.490 | 3/8 | 0.375 | 0.281 | 5/8-11 | 0.875 |
| 1" | 0.998 | 0.996 | 1.312 | 1.287 | 0.625 | 0.610 | 1/2 | 0.500 | 0.375 | 3/4-10 | 1.000 |
| 1-1/4" | 1.248 | 1.246 | 1.750 | 1.723 | 0.750 | 0.735 | 5/8 | 0.625 | 0.469 | 7/8-9 | 1.125 |
| 1-1/2" | 1.498 | 1.496 | 2.125 | 2.095 | 1.000 | 0.980 | 7/8 | 0.875 | 0.656 | 1-1/8-7 | 1.500 |
| 1-3/4" | 1.748 | 1.746 | 2.375 | 2.345 | 1.125 | 1.105 | 1 | 1.000 | 0.750 | 1-1/4-7 | 1.750 |
| 2" | 1.998 | 1.996 | 2.750 | 2.720 | 1.250 | 1.230 | 1-1/4 | 1.250 | 0.937 | 1-1/2-6 | 2.000 |
All dimensions in inches, per ASME B18.3-2012. Abridged — neck, fillet and thread-neck details are in the standard; complete data from our estimating team. Shoulder diameter runs to a close h8-class tolerance.
Standards.
What are shoulder screws?
A shoulder screw is three parts in one: a socket head for driving, a precision-ground shoulder that acts as a shaft or pivot, and a smaller-diameter thread that clamps the shoulder hard against the seating face. Rollers, linkages, dies and guides all run on them.
- Shoulder ground to close tolerance — it is the bearing surface
- Thread is one size down from the shoulder
- Shoulder length is the working length — specify it
- Alloy and stainless as standard
Other names
- Shoulder bolts
- Stripper bolts
- Socket shoulder screws
- SSS (loosely)
Tips for purchasing
- Order by shoulder diameter and shoulder length — the thread follows from the table.
- The shoulder tolerance is what your bushing rides on — tell us the fit you need.
- Stripper-bolt duty in dies is the classic hard service — alloy, through-hardened.
- Certs and traceability on request.
Materials.
Representative capabilities — every item is manufactured or certified to your specification. Confirm requirements with our estimating team.
