uxcell 4mm Tip Diameter HSS Center Spotting Drill Bit Countersinks 10Pcs Product Name : Center Drill Bit;Tip Diameter : 4mm/ 0.16" Shaft Diameter : 10mm/ 0.39";Total Length : 55mm/ 2.2" Material : HSS;Color : Silver Tone Weight : 233g Package Content : 10 x Center Drill Bit