Myself writes: “Like any similar clamp, a spring wound around the pivot forces these jaws shut. In this case, however, one end of the spring works against a movable block. Change the block’s position with a screwdriver, and you can adjust the clamp’s holding force. That little change makes this clamp suitable for applications where its fixed-force brethren might not be appropriate.”
This sounds like something we could use around the shop. We’ve got a number of different clamps, and I’ve even relaxed the springs in some cheap spring clamps to help with more delicate situations, but these seem like they’d do the trick.
The one pictures comes from Highland Woodworking and sells for $3 each. We found dozens on Froogle from $1 and up.