Standard U-bolts are often used to attach pipes or tubes to flat surfaces, while square-shaped U-bolts are used to fasten lumber. If your project requires fastening wood and metal components together, hanger bolts and dowel screws feature different threads on each side to provide a strong, secure connection. 410 Stainless steel hex washer head self drilling screws are hardened to make installation in most materials easier 410 Stainless steel is hardened and rust resistant NOTE: Sheet metal screws provide excellent retention in wood but are very difficult to remove. Head Dimensions for 82° Flat Head Machine Screws ANSI B18.6.3 – 1998. Nominal Size A H J T M R N F G Phillips Driver. Slotted Flat Head Cap Screws Machine Screw.
- 14 Inch Machine Bolt 3 Inches Long Slotted Headboard
- 14 Inch Machine Bolt 3 Inches Long Slotted Headboards
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.
14 Inch Machine Bolt 3 Inches Long Slotted Headboard
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 |
14 Inch Machine Bolt 3 Inches Long Slotted Headboards
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. | |