Hyamass 4-12mm Step Drill Bits, Double Straight Flute Step Bit for Metal

Hyamass 4-12mm Step Drill Bits, Double Straight Flute Step Bit for Metal

• 【Professional-Grade Cobalt Steel Step Drill Bit Set】Crafted with M35 HSS-Co alloy containing 5% cobalt, this cobalt step drill bit set outperforms standard drill bits with 300% longer lifespan. The added cobalt enhances heat resistance for sustained drilling in stainless steel/steel/metal without warping
• 【9 Precision-Sized Bits in 1 Compact Kit】Replace multiple drill bit sets with our 9-step design (4mm-12mm). Laser-etched size markings ensure accurate hole drilling for electrical conduits, plumbing pipes, and sheet metal work. Ideal drill bit kit for mechanics and DIYers needing countersunk holes
• 【Hex Shank + Dual Flutes for Maximum Efficiency】1/4" hex shank prevents slippage in drill chucks, delivering 68% higher torque transmission than round shanks. Double straight flutes accelerate swarf removal during high-speed steel/metal drilling operations
• 【Multi-Material Mastery: From Copper to Carbon Steel】Engineered as the ultimate drill bit set for metal, effectively cutting through stainless steel (304/316), aluminum, copper, iron, and brass. Self-starting tip creates burr-free holes in 1mm-5mm thickness materials
• 【Industrial Durability Meets Workshop Convenience】Hardened M35 cobalt step drill bit set maintains sharpness through 15,000+ RPM operations. Includes protective storage case - your complete countersunk drill bit kit for garage, auto repair, and metal fabrication