A structural fastener like other Lok products with the strength of a bolt
Building on the popularity of its Lok line of structural fasteners, FastenMaster just introduced a fastener that installs like other Lok products but offers the strength of a through-bolt. ThruLok replaces the galvanized 1/2-in. through-bolts commonly used to secure posts, beams, and other deck connections. Deck builders will find that ThruLok fasteners install a bit differently from the bolts they’re used to using, but I think they will warm up to them quickly.
Rather than drilling a hole to receive a bolt, you drive ThruLok fasteners right into the wood like a screw. The key is to leave the fastener head about 1/4 in. shy of being fully seated in the wood. On the opposite side, where the screw threads protrude through the wood, you spin on a proprietary winged nut until it’s finger tight. As you drive the ThruLok fastener that last 1/4 in., the nut tightens to complete the connection and cover the screw’s sharp tip. Two small windows on the nut show a minimum engagement point so that installers and building inspectors can make sure each ThruLok is securely attached for the rated capacity.
ThruLoks are available in 6-1/4-in., 7-in., and 8-in. lengths, and range in price from $2.50 to $3.25 each, depending on length and quantity. My local yard charges $3.15 for a 6-in.-long 1/2-in. galvanized bolt with washers and a nut. Because three ThruLoks are needed to match the strength of two conventional bolts, I’ll spend an extra buck, but I’ll save more than that on the labor because I won’t need to bore the holes.