Timber bolts, also known as economy bolts, dome head bolts, or mushroom head bolts, are commonly used in wood dock construction. 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. Timber bolts are typically manufactured in diameters ranging from ½” through 1-1/2”. Timber bolts are most frequently hot-dip galvanized and manufactured to meet the requirements of ASTM A307 grade A. Stainless steel and high strength ASTM A449 timber bolts are also used for special applications.
| 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 |