Hymnorq 3/8 Inch Fractional Size M35 Cobalt Steel Twist Drill Bit Set of 5pcs, Jobber Length and Straight Shank, Extremely Heat Resistant, Perfect Drilling in Stainless Steel and Cast Iron

COBALT STEEL - Manufactured from M35 grade 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, ideal for repeated drilling in metalworking. 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. 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. 5PC SET - The set includes 5pcs of 3/8” diameter M35 grade cobalt steel twist drill bits, packed in a convinient and reuseable PVC case for easy storage and carrying. Manufactured to German DIN338 standard. DOWNLOADABLE USER GUIDE - We've summed up some tips of drilling metals, including a RPM chart for several common metals, based on our reviews and some articles on the internet. In most cases, our customers would get a much better result with these tips. Welcome to download.