Product Details - Clamping - Workbench Accessories & Plans - Bench Hold-Down

"First, with the arm free to pivot independently all levered forces are exerted downward, without any losses dues to horizontal slippage from the canting action of the hold-down post,

Second, the fine barb-shaped grooves on the post resist upward forces, yet still allow easy entry into a hole. The long, low profile arm is unobstructed at the clamping end, allowing good access to work from all sides.

The 255mm hold-down post gives you 203mm of clamping capacity, matching the 203mm throat capacity. Used vertically in the top of a bench, or horizontally in a side skirt. Clamping forces are infinitely variable by tightening the clamping knob (machined brass) to any degree.