5mm Hex


 A few guitar manufacturers use a 5mm hex tuning nut but these wrenches work well on the standard 3/16" tuning nuts that are 3/8"-3/4" long. 

With the shorter nut length, a standard 3/16" wrench can have problems fitting over the nut due to the nut expanding as it is force threaded onto the rod. This is an issue that the late Bobby Bowman brought to my attention so I started supplying the 5mm Hex wrenches.