12-Point Flange Screws
Handles more torque than standard socket or hex heads.
The integrated flange eliminates the need for a washer; the 12-point head takes higher installation torque in less radial space.
Specifications & technical data.
12-point flange screws to IFI 115 — the compact aerospace-derived head takes a 12-point socket in tight quarters, and the integral flange spreads the load without a washer.
Download our 12-point flange screw dimensioning table (PDF)
| Nominal Size (Basic Major Diameter) | E — Body Diameter | Flange Diameter | F — Width Across Flats | LT — Thread Length (Basic) | Y — Transition Thread (Max.) | |||
|---|---|---|---|---|---|---|---|---|
| Max. | Min. | Max. | Min. | Max. | Min. | |||
| 1/4" | 0.2500 | 0.2435 | 0.375 | 0.365 | 0.252 | 0.244 | 1.000 | 0.25 |
| 5/16" | 0.3125 | 0.3053 | 0.469 | 0.457 | 0.315 | 0.306 | 1.125 | 0.28 |
| 3/8" | 0.3750 | 0.3678 | 0.562 | 0.550 | 0.377 | 0.368 | 1.250 | 0.31 |
| 7/16" | 0.4375 | 0.4294 | 0.656 | 0.642 | 0.438 | 0.429 | 1.375 | 0.36 |
| 1/2" | 0.5000 | 0.4919 | 0.750 | 0.735 | 0.502 | 0.493 | 1.500 | 0.38 |
| 9/16" | 0.5625 | 0.5538 | 0.844 | 0.828 | 0.564 | 0.555 | 1.625 | 0.42 |
| 5/8" | 0.6250 | 0.6163 | 0.938 | 0.921 | 0.627 | 0.618 | 1.750 | 0.46 |
| 3/4" | 0.7500 | 0.7406 | 1.125 | 1.107 | 0.752 | 0.743 | 2.000 | 0.50 |
| 7/8" | 0.8750 | 0.8647 | 1.312 | 1.293 | 0.877 | 0.866 | 2.250 | 0.56 |
| 1" | 1.0000 | 0.9886 | 1.500 | 1.479 | 1.003 | 0.991 | 2.500 | 0.62 |
| 1-1/8" | 1.1250 | 1.1086 | 1.688 | 1.665 | 1.128 | 1.115 | 2.750 | 0.71 |
| 1-1/4" | 1.2500 | 1.2336 | 1.875 | 1.852 | 1.253 | 1.240 | 3.000 | 0.71 |
| 1-3/8" | 1.3750 | 1.3568 | 2.062 | 2.038 | 1.378 | 1.365 | 3.250 | 0.83 |
| 1-1/2" | 1.5000 | 1.4818 | 2.250 | 2.224 | 1.503 | 1.489 | 3.500 | 0.83 |
All dimensions in inches, per IFI 115-2014. Abridged — the complete table including head height, wrenching and gaging dimensions is available from our estimating team.
Standards.
What are 12-point flange screws?
A 12-point flange screw puts a compact double-hex drive on top of an integral washer flange. The 12-point socket engages every 30 degrees and swings in tighter arcs than a hex, while the flange spreads clamp load without a separate washer — which is why they run high-strength joints in engines, gearboxes, and confined machinery.
- 12-point external drive — fine engagement, small swing arc
- Integral flange replaces the washer
- High-strength alloy as standard
- Compact head for counterbores and tight clusters
Other names
- 12-point bolts
- Double hex flange screws
- Ferry cap screws (trade name)
- 12-point cap screws
Tips for purchasing
- Check the flange diameter against your spot-face — it is the bearing surface.
- 12-point sockets, not hex — make sure the tooling matches.
- High-strength alloy standard; stainless and exotics to order.
- Certs and traceability come standard.
Materials.
Representative capabilities — every item is manufactured or certified to your specification. Confirm requirements with our estimating team.
