Open-ended wrenches come in metric sets graduated in millimeters or SAE (Standard American English) sets graduated in fractions of an inch. If you need to buy one for a particular job, it’s ...

Jaw design can influence the strength of open-end wrenches. “Every so often some wrench manufacturer comes out with a V-shape in the back of the jaws on their open-end wrenches,” says Tom ...

A reader says this is the smallest open-end wrench in the world, with 0.005 in. across the flats on one end and 0.010 in. across the other. The human hair next to the wrench gives a comparative size.