HSS-Co Drill Set for high strength steel, such as stainless steel. It is difficult to machine the workpiece can be processed in stainless steel, tool steel, through heat treatment, M35 high speed steel cobalt for high hardness, high wear resistance and high hardness. Cobalt alloy to improve heat resistance that will work and exceed normal HSS bits, especially if your work involves difficult metals Radial drill, bench drill or manual drill chuck can be used for drilling operations. Details: Portable and stationary use (in punch press). 135 point split point tip. Surface treatment: Roasted Yellow Diameter: 1-13mm Shank: Round Application: Stainless steel, steel, iron, aluminum and other metal pipes job openings. Note: Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Material: HSS-Co M35 Cobalt colour: As Shown Package Contents: 1 x M35 Cobalt Drill Bit set(25pcs) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.