HPC's Metal Punch and Die Set is an essential tool for installing vending machine locks and cam locks on metal cabinets, desks, lockers, file cabinets and cash boxes. It punches a double "D" hole in single-wall sheet metal up top 18-gauge (.048-inch / 1.2 mm). The hole measures .645-inch x .770-inch (16.5 x 19.5mm) hole to fit standard cam locks.