The pipe clamp racks are a perfect fit for 3/4 inch Jorgensen pipe clamps and also work fine with 1/2inch versions. The bar clamp racks are a perfect fit for Bessey K-Bodies. They also work fine with Jorgensen bar clamps, both regular and heavy duty style, although the width of the slot means these are free to twist a bit. The bar clamp racks are marginal at best for holding Bessey "Tradesman" bar clamps, however. The opening in the upturned lip at front is not wide enough to allow to these clamps to seat properly: they're prone to falling off if knocked lightly.