... have long life We manufacture annular cutters / Magnetic drill with CNC machines and we have many cutters ... of different sizes in stock. Magnetic drill(Mag drill)Weldon shank & one touch shank annular cutters ... material,size from12mm-100mm,depth25mm,30mm35mm,,50mm,55mm,75mmCan drill iron sheet ,stainless steel,etc. Abrasion resistance, ... .Tin coated is also OK. Magnetic drill Drill Bit