Home Made Bench Clamp

When I bought this house the previous owner had built benches attached to the walls in the garage.   As I began, again, to do woodworking I needed some way to hold boards while I marked them or edged them, so I came up with this bench clamp.   I cut two slots int the bench top, which was made of 1/2" plywood, and attached 3/8" flat strap on each side of the slot on the bottom.   I bought two long 3/8" carriage bolts and ground the heads so they could be inserted down into the bench slots then turned 90° to hold.   I ripped a 2x4 to make two 1.5" square wooden bars about 14" long and slotted them length wise.   I attached more flat 3/8" strap on each side of slot in the bars, and made two handles with tee nuts.   I also made a pair of rear supports to elevate the back end of the bars when gripping different thicknesses of board.   I don't use these much anymore since I have my woodworking bench with tee tracks and clamps, but they still come in handy some time.   Here are the pics.

The bottom end of the ground off 3/8" carriage bolt.   You can push it down through the slot in the bench then rotate it 90° and tighten it.   The flanges catch against the 3/8" flat metal strips beside the slot under the bench.   You can see the slot in the bar and slot in the bench, you can just see the edge of one of the flat strap on top of the wooden bars.

You can just see the 3/8" flat strap under the bench beside the slot.

The handle with it's washer, you can also see the square shoulder on the head of the 3/8" carriage bolt (keeps the bolt from turning when tightening).

You can see the flat straps on top of the clamp bar and the tee nut on top of the handle.

Heres what is looks like with both clamps on a board.

I put a mark on the end of the 3/8" carriage bolt to tell which way the head is turned.

The back end elevator.

The clamps store neatly in one of the drawers I built under the bench.