Golden Spiral Cam Clamp

This is a surface cam clamp to hold stock on a workbench. The more you push against it, the more it holds the stock; this is ideal for hand planning small pieces. The clamp is to be coupled with a 20mm metric bolt, that will fit a 20mm hole in the workbench. There are a left and a right version, but one piece is sufficient to hold firmly if you already have standard holders.