Timber bolts are also referred to as dome head, fender head, safety head, and mushroom head bolts. In the Pacific Northwest, they are referred to as economy bolts. They are used in marine and wood applications.
The underside of the large, rounded, low-profile head of a timber bolt has two nubs or fins which prevent the bolt from turning in the timber. The oversized timber bolt head eliminates the need for a malleable iron washer, and therefore reduces costs.
Manufacturing
Portland Bolt manufactures timber bolts from 1/2″ diameter through 1-1/2″ diameter in most ASTM, AASHTO, and SAE specifications. Special timber bolt tooling can be created to produce nonstandard head dimensions or bolt heads with your company’s name and/or logo.
Standard Thread Length
Bolt lengths ≤ 6″: Thread length = (2 X diameter) + 1/4″
Bolt lengths > 6″: Thread length = (2 X diameter) + 1/2″
Note: Most stock timber bolts longer than 12″ in length will have either 6″ or 8″ of thread.
Stock
Grade: A307
Diameters: 3/4″
Lengths: 8″ – 36″ in 2″ increments
Origin: Domestic
Finish: Hot-dip galvanized
Stock Thread Length
Bolt lengths ≤ 12″: 4″ thread
Bolt lengths 14″-16″: 6″ thread
Bolt lengths ≥ 18″: 8″ thread
Timber Bolt Dimensions
| Bolt Diameter | D | F | H |
|---|---|---|---|
| Body Diameter Max | Head Diameter | Head Height | |
| 1⁄2 | 0.515 | 11⁄2 | 1⁄4 |
| 5⁄8 | 0.642 | 115⁄16 | 5⁄16 |
| 3⁄4 | 0.768 | 21⁄4 | 3⁄8 |
| 7⁄8 | 0.895 | 25⁄8 | 7⁄16 |
| 1 | 1.022 | 27⁄8 | 1⁄2 |
| 11⁄8 | 1.149 | 27⁄8 | 1⁄2 |
| 11⁄4 | 1.277 | 27⁄8 | 1⁄2 |
| 13⁄8 | 1.404 | 3 | 3⁄8 |
| 11⁄2 | 1.531 | 3 | 3⁄8 |
Stock Timber Bolts
| Length | Diameter |
|---|---|
| 3/4" | |
| Galv. | |
| 8 | 18549 |
| 10 | 18553 |
| 12 | 18557 |
| 14 | 18561 |
| 16 | 18565 |
| 18 | 18569 |
| 20 | 18573 |
| 22 | 18577 |
| 24 | 18581 |
| 26 | 18583 |
| 28 | 18585 |
| 30 | 18587 |
| 32 | 18589 |
| 36 | 18595 |
| Other sizes and finishes available on request. | |