Review on Stahlwille CROW FOOT Wrench Inside Square by Robert Jackson

Jaw clearance is 13mm (0.513"), which is 0.002" more than the maximum SAE specification for wrench tolerance. If you have a nut/bolt head that is too small, even if it's SAE specs, this assembly will round out the hex corners and you may not be able to tighten to spec. The problem is compounded when tightening 300 series stainless steel nuts/bolts due to the softness of steel. I am returning this unit because I believe it is actually 13mm, mislabeled as 1/2 inch. I bought two and when I get the other one I will do the same if it doesn't meet industry standards.