Tension Control Bolts
Tension Control Bolts, also called TC Bolts, A325 TC(ASTM F1852) or A490 TC(ASTM F2280) bolts, have an extension that is grooved (referred to as the spline) that is designed to ensure accurate, repeatable, and visible indication of proper tension levels with each installation.
Tension control bolts have a button head as opposed to the hex head of regular structural bolts and always come as an assembly with a nut and washer. They require an electric shear wrench to install. To achieve the correct tension, the wrench turns the nut clockwise, while turning the spline counterclockwise. When the right tension level is reached the spline snaps off – giving consistent, repeatable, and visual indication of accurate tension levels.
We stock standard sizes of A325 tension control bolts including the following:
- 3/4″ x 1 3/4″ A325 tension control bolts
- 3/4″ x 2″ A325 tension control bolts
- 3/4 x 2 1/2″ A325 tension control bolts
We stock many other sizes and can get any size that we don’t have in stock. Atlantic Bolt also has material test reports (MTRs) on file digitally for all our structural bolts.
(In 2016 the ASTM introduced the new umbrella specification F3125. F3125 encompasses six other ASTM standards, including A325, A325M, A490, A490M, F1852, and F2280. Currently, the F3125 specification is slightly less known and the A325, A325M, A490, A490M, F1852, and F2280 specifications are still how our customers refer to these bolts. As such, until the ASTM removes the A325, A325M, A490, A490M, F1852, and F2280 standards, we will continue to use the existing A325, A325M, A490, A490M, F1852, and F2280 specifications to reference these bolts.)