T-Bolt
Bolts · t-slot bolt · hammer head bolt · extrusion bolt
Definition: A T-bolt has a rectangular head that drops into a T-slot in aluminum extrusion, where it is turned and tightened to clamp panels and brackets.
Anatomy
■ Head■ Shank■ Threads■ Point
Governing standards: Manufacturer specified (no universal standard)
Common Sizes
| Inch | Metric | Head width | Head height |
|---|---|---|---|
| 5/16-18 | M8 | — | 3/4 to 2 long |
| 1/4-20 | M6 | — | 1/2 to 1-1/2 long |
| #10-32 | M5 | — | 3/8 to 1 long |
Representative sizes. Full dimensional data lives in the standards listed below.
Grades & Strength
| Grade | Material | Tensile (psi) | Marking |
|---|---|---|---|
| Zinc-plated steel | steel | — | None |
| Stainless steel | stainless steel | — | None |
Materials
- Zinc-plated steel
- Stainless steel
Pros & Cons
Pros
- Slides anywhere along a slot
- Strong clamping into extrusion
- Reusable
Cons
- Only fits the matching slot series
- Head can twist in a worn slot
- Needs end access or a drop-in notch
Typical Uses
- Aluminum extrusion framing
- Machine guarding
- 3D printer frames
- CNC fixturing
Alternatives & Related
- Hex Bolt — Where the nut side is accessible
- Square Nut — Slides in a T-slot when used with a bolt
Where to Buy
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FAQ
How do you install a T-bolt?
Drop the T-head into the end of the slot (or a drop-in access hole), turn it 90 degrees, and tighten the nut or the part against the extrusion.
What size T-bolt for 2020 extrusion?
2020 (20 mm) extrusion commonly takes M5 or M4 T-bolts; 4040 takes M8. Match the bolt to the slot series.