ThruLok Structural Bolts

The ThruLok screw is designed to be an easy-install through-bolt fastener as an alternative to carriage bolts and nuts. ThruLoks still require pre-drilling, but driving the bolt in only requires a drill or ratchet from the outside, rather than than the inside.

ThruLoks are limited on the framing thickness they can secure:

6-1/4" can reach from 4-1/2" to 5-1/4" of framing.

7" can reach from 5-1/4" to 6" of framing.

8" can reach from 6-1/4" to 7" of framing.

If your framing is thicker than the dimensions shown here, the nut will not have enough thread to tighten. If the framing is less than the minimum, the nut will bottom out, and not allow you to tighten it any more.