This easy-to-build hold-down clamp adds great clamping versatility to any workbench and is quick to install. Our thanks to reader Tom Peniston for a great design. You’ll need:
- Pipe clamp hardware, either for 1/2-in. or 3/4-in. pipe
- Pipe nipples: A 5-in. nipple allows the clamp jaw to tighten against a 3/4-in. thick bench top, and it gives an opening capacity of 1-1/4 in. Use longer nipples to increase the capacity.
- Threaded ﬂoor ﬂanges
- Two 4-in. square pieces of 1/2-in. plywood with 1-1/8 in. holes drilled in the center.
To install the clamps on a work surface, drill holes with a spade bit (1 in. for 1/2-in. pipe and 1-1/8 in. for 3/4-in. pipe) where you want to position the clamps. Screw ﬂanges under the hole using a plywood piece between the ﬂange and bench top so the ﬂange sits square and ﬁrm (see photo). Now any time you need hold-down clamping, just screw the clamp and nipple into the hole and you’re ready to hold boards for routing, sanding and sawing.