Hardness up to HRC 65 Superior Performance: The 5/8 metal drill bit set for steel is made of high-speed steel with hardness up to HRC 65, offering excellent wear, and heat resistance Sharp & Precise: The HSS jobber drill bit set features a 118° split point to improve concentricity and prevent walking, enabling faster, more accurate drilling U-type Slot Design: The... 1.8Mm Mtsooning 10 Pcs 1.8Mm Micro Hss Twist Drill Bit Straight Shank Electric U-type Slot Design: The split point drill bit features a spiral flute and U-type slot design that promotes fast chip removal, reduces friction and heat buildup, and ensures smooth, stable drilling performance 118 degree split point Widely Used: Jobber-length twist drill bits suit soft metals like copper and aluminum, wood, plastic, and other non-ferrous materials. Provides additional stability in tough applications HSS 5/8" HSS Twist Drill, 1/2" Reduction Shank, 118 Degrees, Black For High Speed Steel Drill Bits Of Stainless Steel, Iron, Wood, Aluminum Alloy 5/8 Drill Bit Expand the size range of drill chuck, compatible with most drill devices. HSS Reduced Shank Drill Bit at Rs 10/piece | HSS Taper Shank Drill... Attention: 1., Low speed control: 200 to 1000 rpm 2., Fixed well to avoid the drill bit breaking due to vibration., 3., If the chip remove is abnormal, please stop drilling immediately and continue after remove., 4., When drilling for a long time, please use oil for cooling to prolong the service life., 5., Due to the large diameter of the drill, it is need to pre-drill the holes with a smaller diameter drill and then reaming the holes with a larger diameter drill for best results. HSS Drill Bit Set for Steel with Excellent Drilling Performance