These second generation spigot jaws have been designed to give an improved grip when working with green wood. Similar in operation to a pin chuck, the spigot jaws are inserted into a 30mm diameter by 50mm deep hole in the blank and the jaws expanded into the hole. It is important to use the full depth of the jaws in order to give the best possible grip and to avoid over-stressing and damaging the jaws. Should the grip loosen during turning then another tweak on the key will soon restore it.