**Auniwaig 7.1mm HSS Twist Drill Bit Set - 5pcs High Speed Steel Jobber Drill Bits for Steel & Aluminum Alloy - Perfect for Metalworking, Woodworking & DIY Projects**

The difference between the two materials High-speed steel 6542 (M2) has good process performance, good strength and willfulness, and is mainly used to manufacture complex thin-edged and impact-resistant metal cutting tools, while high-speed steel 4241 is generally used to manufacture high-temperature bearings and cold extrusion dies, etc. Reduced Shank Drills Reduced shank drills expand the size range capacity of a portable drill chuck. Common flute and overall length for minimal adjustment during tool changes. The effect of punching is connected with the material and hardness of the hole. The higher the material hardness, the longer it takes. Adjust the relative position of the bit before grinding,do not ignore the bevel angle in order to flatten the edge,or ignore the flattening edge in order to flatten the axis.Also,the tail of the bit should not be higher than the horizontal center line of the grinding wheel. Precautions for Use 1. Before drilling, mark the position where you need to drill. If it is a material with a relatively smooth surface, it is recommended to cover it with clay and other items to avoid the drill bit from slipping on the surface of the product. 2. When drilling, you need to add water while drilling, or directly put the product into the water to drill, which can effectively reduce the wear and tear of the product in use. 3. Drilling needs to be effected at high speed, smooth and without shaking, lightly press, and can't be squeezed hard. SHARP CUTTING Grinding in multiple processes, the cutting edge is sharp, the cutting resistance is small, and the hardness is high SMOOTH CHIP EVACUATION Spiral flute design reduces clogging and smooth chip evacuation UNIVERSAL ROUND HANDLE Round shank design, easy clamping, tight clamping, no slippage

【SPECIFICATIONS】- Twist Drill Bits Diameter 7.1mm / 0.28-inch; Shank Diameter 7.1mm / 0.28-inch; Total Length 110mm / 4.33-inch; Drill Bit Length 80mm / 3.15-inch; Material HSS-4241; Hardness 62-63HRC.

【TWISTED DESIGN】- With the twisted design, it can improve cutting accuracy by centering the tip. It can avoid displacement of the drill bit during work, and at the same time remove debris and particles faster and easier.When it cannot penetrate, try to adjust the RPM.

【HIGH QUALITY MATERIAL】- Twist Drill is made of high speed steel, high speed steel construction is designed for durability and extended tool life.

【FEATURE】- Fully ground spiral groove design clears particles quickly,decreases friction and heat for faster drilling performance.

【APPLICATIONS】- Perfect for stainless steel, copper, aluminum alloy, as well suit for wood, plastic. Please keep cool and gentle using, the working life of the twist drill bits can be largely prolonged by proper usage.