How to Make a Woodworking Hold-Down Clamp

Draw three sides of a rectangle onto the face of a 1 1/2 inch thick piece of hardwood such as oak. Draw the "vertical" side of the rectangle to a length of 11 inches. Draw the other two "horizontal" lines to a length of 13 inches. Use a contractor’s square to ensure the corners of the rectangle shape are 90-degree angles.

Draw a second vertical line 1 inch inside the rectangle from the first vertical line, then draw two horizontal lines inward 1 inch from the first set of horizontal lines. This gives you two perfectly square rectangle shapes. Draw a vertical line between the ends of each set of horizontal lines. This completes the C-shape of the clamp. This clamp will give you a throat height of 8 inches and a throat depth of 12 inches. If you need more, you can adjust the height and length of the outline to meet your needs.

Cut the C-shape out with a band saw. Sand the rough edges with a block sander equipped with 600-grit sandpaper.

Stand the C–shape up on one of its legs so it rests on the thin edge. Place a mark 1 1/2 inches inward from the end of the top leg on the C-clamp.

Drill a hole through the top leg with a 7/16 inch drill bit.

Cut a piece of 1/2 inch coarse threaded rod to a length of 12 inches with the band saw.

Drill a 1/4-inch hole through the threaded rod, 1/2 inch down from one end of the rod.

Slide the shaft of a screwdriver through the hole in the threaded rod. Use the screwdriver to thread the rod into the hole you drilled in the wooden clamp. The threaded rod must cut the threads into the wood, so the first time you place the rod into the wood, expect to use force.

Cut a 1-inch square piece of hardwood out of 1 inch thick wood stock. Drill a hole in the center of the wooden block with a 7/16 inch bit. Drill the hole half way through the piece of wood.

Thread the wooden block onto the threaded rod that now rests between the two legs of the C-clamp. The wooden block presses against the wood you plan to clamp to protect the wood from the end of the threaded rod.