Check the listing for details. 4 Pcs 4mm Solid Carbide Drill Bits Straight Shank Jobber Drill Bits for Drilling. Color: Silver, Condition: New. Listed at 20.90 USD. Specifications:Drilling Diameter: 4mm / 0.157"Flute Length: 26mm / 1.02"Shank Diameter: 4mm / 0.157"Overall Length: 43mm / 1.69"Material: YG6/C2/K20 Tungsten CarbideFinish: UncoatedCutting Hardness (Max.): HRC45Package Content: 4pcs x Twist Drill BitsDescriptions:Constructed from medium grain YG6/C2/K20 tungsten carbide, the drill bit has good toughness, high hardness (HRA89) and wear resistance. With good milling and cutting performance, can ensure high work efficiency. Carbide tool offers long tool life and faster cutting speeds than other substrates.Widely used for drilling non-ferrous metal, cast iron, stainless steel, aluminum, copper, alloy steel, plastic, wood, etc.. Designed with the base substrate without any additional coatings, suitable for wide ranges of applications.Spiral chip space design for fast and clean chip removal.