Hymnorq 4.2mm Metric M35 Cobalt Steel Extremely Heat Resistant Twist Drill Bit Set of 10pcs with Straight Shank to Cut Through Stainless Steel Cast Iron and Other Hard Metals
- SELF CENTERING - The 135°quick-cut pilot split points are self-centering and can penetrate quickly with less pressure. The bits will not "walk" or "wander". Straight shank allows for firmly holding and accurate centering, fit for standard drill chucks and regular round collet chucks.
- COBALT STEEL - Manufactured from M35 cobalt steel, with molybdenum and cobalt added to creates a hardened alloy, measuring Rockwell hardness up to 67, for much faster cutting and extra longer life span, with up to twelve times when compared with an average HSS drill bit.
- FOR METALWORKING - Particularly successful in cutting through hard metals(hardness less than HRC38°) such as stainless steel and cast iron, although they can be used for softer materials like copper and aluminium, too. Not for hardened steel / high carbon steel. Try to adjust the RPM when it fails to penetrate.