Uxcell 5/16-18 Unc Straight Flute Tap Left Hand And 6.5Mm Twist Drill Bit Set, Tap and Drill Bit: Tap thread size: 5/16-18 UNC, drill bit diameter: 6.5mm / 0.26". High-speed steel tool has high hardness and toughness for wear resistance. Straight Flute Tap: Straight flute design, downward chip removal. Left hand thread cutting, fast tapping with accuracy. Suitable for processing through holes. For drilling and tapping aluminum, die steel, stainless steel, bronze, hard plastics Twist Drill Bit: Spiral chip space design for fast and clean chip removal. Sharp cutting edge provides smooth cutting and no glitches. Titanium coating provides excellent corrosion resistance and improves wear resistance. Usage of Tap: Used on drilling machines, tapping machines, CNC and milling machines. Use with tapping oil to get higher quality threads and more durable taps. Machine taps are suggested to be used with tap collets with overload protection. Tips of Drill Bit: Suitable lubricant is conducive to cutting or cooling, making cutting easier, improving smoothness and dimensional accuracy. Select an appropriate feed rate and cutting speed to improve the tool life.