Threaded Rod
Studs & Rods · all thread rod · allthread · ready rod · fully threaded rod
Definition: Threaded rod is a continuous, headless bar with external threads along its full length, cut to size and used with nuts on both ends.
Anatomy
■ Head■ Shank■ Threads■ Point
Governing standards: ASME B18.31 · ASTM A307 · ASTM A193
Common Sizes
| Inch | Metric | Head width | Head height |
|---|---|---|---|
| 1/4-20 | M6 x 1.0 | — | ≈ 0.12 lb/ft |
| 3/8-16 | M10 x 1.5 | — | ≈ 0.28 lb/ft |
| 1/2-13 | M12 x 1.75 | — | ≈ 0.50 lb/ft |
Representative sizes. Full dimensional data lives in the standards listed below.
Grades & Strength
| Grade | Material | Tensile (psi) | Marking |
|---|---|---|---|
| Grade 36 (A307) | low carbon steel | 58,000 | None / color-coded |
| Grade B7 | Cr-Mo alloy steel, Q&T | 125,000 | B7 (often stamped) |
| 18-8 stainless | 304 stainless | 70,000 | None |
| Grade B8 | 304 stainless, strain-hardened | 75,000 | B8 |
Materials
- Zinc-plated steel
- Hot-dip galvanized steel
- 304 / 316 stainless steel
- B7 alloy steel
Pros & Cons
Pros
- Cut to any length on site
- Cheap and universally available
- Works from both ends with nuts
Cons
- Exposed threads can be damaged or corrode
- No head means both ends need nuts
- Zinc rod is for indoor or light use only
Typical Uses
- Hanging pipe and ductwork (trapeze)
- Bracing and tie-downs
- Anchor bolt tie-ins
- Custom-length bolts
Alternatives & Related
- Hex Bolt — For standard headed fastening in a known length
- Hex Nut — Used in pairs to clamp rod assemblies
Where to Buy
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FAQ
What grade of all thread should I use?
Grade 36 zinc for general hanging; B7 for high-strength structural and high-temperature service; stainless for corrosion resistance; B8 stainless for corrosion plus strength.
How do you cut threaded rod cleanly?
Thread a nut on past the cut line, cut with a hacksaw or grinder, then unthread the nut to chase and clean the burred thread.