Double End Twist Drill Bits for Metal Cutting

Metallurgical Composition: Produced from top-tier high-speed steel—including HSS4341, M2, and M35 grades—with a post-treatment hardness range of HRC 62–65. The M35 versions contain 5% cobalt, which notably improves resistance to heat-induced softening and abrasive wear, extending service life. The M2 formulation provides a practical compromise between affordability and essential cutting functionality. A comprehensive thermal treatment protocol—incorporating quenching followed by multiple tempering stages—ensures homogeneous hardness distribution across the entire drill body, combining effective cutting action with resilient toughness.   Geometric Configuration: Designed with a conventional 118° tip angle (with an optional 135° split-point configuration for harder workpieces), coupled with a 30° helical groove and an 8° clearance angle. Each cutting lip undergoes precision grinding and micro-honing to achieve exceptional keenness, thereby lowering cutting forces and facilitating pre…