Park Tool Axle & Pedal Vice Designed to securely hold 5/16” to 9/16” axles for easy wheel hub & pedal adjustments, the AV-4 is a must for every mechanic's workbench. Just insert axle into one of the three precision-machined openings & tighten in a bench vise. The AV-4's bridge spring keeps the jaws aligned & allows the tool to automatically open when the bench vise is opened. Aluminum jaws won't damage axle threads.