I bought these for an upcoming bookshelf project and when I first tested them I realized how poor the handle design was . If you don't have a handle hanging off the edge of the workbench, you can only tighten the clamp half a turn. Then you need to push the rod back and tighten another half turn. Terrible design. I removed the clamp bar and made Bessie style grips. Clamps are now much easier to use. They seem to be working on leveling the bookshelf for assembly. The time will show.