25PCS High Speed Steel Roll Forged Black-oxided Twist Drill Bit Set HSS Drill Bit

25PCS High Speed Steel Roll Forged Black-oxided Twist Drill Bit Set HSS Drill Bit. High Speed Steel Material: Made from premium HSS 4241 with hardness up to 68 HRC for superior cutting performance. Roll Forged Process: Manufactured using roll forged technology for enhanced strength and durability. Customized Options: Offers full customization including OEM, logo marking, and customized packing. Black Oxide Finish: Surface treated with black oxide for improved corrosion resistance and aesthetics. DIN338 Standard: Complies with DIN338 standard ensuring high precision and international compatibility. Multiple Material Grades: Supply options include T-4241, 4341, 9341, M2, M35, and M42 based on requirements. Comprehensive Quality Control: Strict inspections cover raw materials, hardness, tolerance, and final packaging.