Uploaded June 2026 | Updated September 2026, 2 days ago
There's one bolt that's noticeably different from most others: the carriage bolt. These bolts were originally used on horse-drawn carriages. The smooth head worked great as an exterior fastener because nothing could easily snag on it.
Unlike a hex bolt, the head is completely smooth. There isn't a place for a wrench, socket, or screwdriver.
So how do you tighten it?
The secret lies just below the head. After drilling a hole the same size as the bolt's shank, the square neck is driven into the wood.
Once it's seated, the bolt locks itself in place, allowing the nut to be tightened from the opposite side.
From my experience using these fasteners, the biggest problem isn't the square neck itself. It's not getting the bolt fully seated before tightening the nut. When that happens, the corners can strip the wood fibers instead of biting into them.
If you want carriage bolts to work properly, hammer them in firmly like you would a nail. If you're working with plywood or other delicate stock, add a washer and nut to the opposite side and slowly pull the bolt in until the square neck is fully seated.
Because the head is round and easy to hide, I've found carriage bolts make great hidden threaded studs. When making shop knobs, I'll drill and recess the diameter of the head, pull the bolt into place with a washer and nut, then lock it permanently with epoxy. Once cured, you've got a custom threaded knob that's incredibly strong.
Like step by step projects? Check out the second channel! → @makethingswithrob
Become a patron! → patreon.com/makethings ←
Huge thank you to my patrons that keep this thing going!
*MAKER TEAM*
Michelle B
Keith Current
Rich Lightfoot
Tutor the Barbarian
Aubrey G.
Nukebert
Sam W.
Aaron Knows DIY
G. Salazar
David B.
Marc B.
Richard B.
Ben. K
Bill Patterson
D. Lundman
Make Things
#MakeThings #mtbitesize
There's one bolt that's noticeably different from most others: the carriage bolt. These bolts were originally used on horse-drawn carriages. The smooth head worked great as an exterior fastener because nothing could easily snag on it.
Unlike a hex bolt, the head is completely smooth. There isn't a place for a wrench, socket, or screwdriver.
So how do you tighten it?
The secret lies just below the head. After drilling a hole the same size as the bolt's shank, the square neck is driven into the wood.
Once it's seated, the bolt locks itself in place, allowing the nut to be tightened from the opposite side.
From my experience using these fasteners, the biggest problem isn't the square neck itself. It's not getting the bolt fully seated before tightening the nut. When that happens, the corners can strip the wood fibers instead of biting into them.
If you want carriage bolts to work properly, hammer them in firmly like you would a nail. If you're working with plywood or other delicate stock, add a washer and nut to the opposite side and slowly pull the bolt in until the square neck is fully seated.
Because the head is round and easy to hide, I've found carriage bolts make great hidden threaded studs. When making shop knobs, I'll drill and recess the diameter of the head, pull the bolt into place with a washer and nut, then lock it permanently with epoxy. Once cured, you've got a custom threaded knob that's incredibly strong.
Like step by step projects? Check out the second channel! → @makethingswithrob
Become a patron! → patreon.com/makethings ←
Huge thank you to my patrons that keep this thing going!
*MAKER TEAM*
Michelle B
Keith Current
Rich Lightfoot
Tutor the Barbarian
Aubrey G.
Nukebert
Sam W.
Aaron Knows DIY
G. Salazar
David B.
Marc B.
Richard B.
Ben. K
Bill Patterson
D. Lundman
Make Things
#MakeThings #mtbitesize
