Making A Bar Clamp From Wood And Steel Clamps & Vises
I’ve made several different types of clamps, but most have used just wood for all of the major parts. This one makes use of steel for some key parts, where the strength and durability of the metal will make the most difference. The goal was to make a lightweight clamp that is not overly bulky, yet is also strong and easy to adjust. I think this fits the bill.
I started with the bar itself. After cutting it to length, I carefully marked the locations for the pins that hold the fixed jaw on. I used a centre punch to make a divot in the steel to help guide the bit accurately:
I’m using a step drill and drilling the holes to 3/16″. These will be reamed out to their right size after the fixed jaw is glued on. I’m using a step drill, but a regular twist drill would also work just as well.
The bar needs shallow notches for the moving jaw to lock on, and the easiest way to make them is with a triangular file. It didn’t take long, less than 5 minutes:
I’m using 1/4″ spacing for these, but you could widen that out to 1/2″ or 3/4″ to reduce the amount of work. I think that the 1/4″ spacing is perfect and will actually save you time in the long run, since it takes less turns of the clamp handle to tighten it.
The trickiest part to make is the plate that the bar fits into. In particular, the slot. I found the best way is to drill a series of holes, then cut out the material that is left with either a small, round file, or a Dremel with a thin cutting disk:
Another (more dangerous) way to remove the steel between the holes is with the drill bit, angling the bar up and down so that the sides of the bit cuts. The risk here is the bit can break while doing this:
When the bulk of it has been cut out, I used a round chain saw file (5/32″) to clean it up. It does not need to be perfect, but the bar must slide through it easily:
At the other end of this plate, a hole needs to be tapped to match the threading on the lead screw.
To guide the tap in square to the plate, I drilled a hole in a piece of wood and used the drill bit to line it up. I could then clamp that firmly and run the tap through it:
The last steel part is the locking plate. I drilled and countersunk the screw hole before cutting it off from the longer piece – safer and easier to drill that way:
The end needs to be beveled to match the notches in the bar, and I did that on my small belt / disk sander:
On to the wooden parts. The moving jaw needs a recess cut into it for the locking plate, and I did that by nibbling the wood away on the table saw using my mini table saw sled:
It also needs a slot cut into the end for the bar to slide freely through. To line up the plate in the right place on the moving jaw, the bar is slipped into the slot and brought up tight to the bottom of the slot in the jaw. The plate is then pulled tight against the other side of the bar:
The plate and the jaw are clamped together in that position and the lead screw hole can be marked with a brad point bit:
The hole through the wood in the moving jaw can be tapped, or just drilled out large enough for the lead screw to slip through. I chose to tap mine, since it will add strength and doesn’t take much longer to do.
The plate is used to mark a pilot hole for the screw that will hold it on. On the other side of the moving jaw, the locking plate is put in place to check if it’s a good fit. With the bar in the slot and the locking plate engaged in a notch in the bar, the bar should be square to the moving jaw. You can adjust the locking plate to fix this if the bar is out of square:
The fixed jaw gets glued to the bar with epoxy and pinned. I drilled the pin holes undersize and will use short pieces of threaded rod for the pins. Easier is to use just straight 1/4″ rod, but I didn’t have any on hand for this:
The clamp pad is made from 5/8″ thick plywood with a counterbore deep enough for the nut plus the washer to fit into:
I didn’t have any 5/8″ plywood, so I cut this down from 3/4″. Solid hardwood can also be used for the clamp pad parts.
All of the parts prepared and ready for assembly:
Before gluing the bar into the fixed jaw, I roughed it up with sand paper and wiped it clean with alcohol. The bar and the filler are glued in with 5 minute epoxy and set aside to dry for an hour or so:
While the glue is drying on that, the plates can be fastened to the moving jaw:
The lead screw needs a notch to key it to the handle before gluing it in, and I did that with a round file. After the epoxy on the fixed jaw had set for a while, I drilled out the pin holes to the right size. This fixes any alignment problems between the two:
I used a 1/4″-20 tap to thread the holes, then got some epoxy in there before screwing in the pins. I cut shallow slots in the ends of the pins with a hacksaw, and that makes it possible to use a screw driver:
The fixed clamp pad is glued on and clamped. Note the grain direction of the pad – it goes across the jaw:
The filler is glued into the moving jaw and clamped. While that’s drying, I threaded in the lead screw and glued on the handle. The notch I cut in the lead screw should face down, so that it will fill with the excess epoxy:
The retainer is slipped on and the nut is glued to the end of the screw with epoxy. I left these to set for a couple of hours before moving to the next step.
With the washer in the clamp pad, I put some grease on the end of the lead screw and glued the pad to the retainer. After these go together, the clamp pad should move freely:
To keep the moving jaw from sliding off the bar, I put a small bolt in the end.
Finished and ready for duty. I like how efficient the design of this clamp is, using a minimum of parts to get the job done. I also like how light and easy to use it is, and I’ll likely build a few more of these in the near future.
I made a video that covers the assembly of the clamp: