This durable engineering quality HSS ground drill is designed for drilling sheet metal and wood with a 1/4 hex chuck impact driver. The quick change shank can be rapidly interchanged for easy and hassle free drilling. Diameter mm: 3.5 Working Length mm: 39 Total Length mm: 84 Shank Dia. inch: 1/4 Timco Impact Drill Bit (Size 3.5mm - 1 Each) in Black