Description:

Twist Drill Bit: Cutting edge diameter: 16.5mm / 0.65", 17mm / 0.67", shank diameter: 1/2". Features high hardness, good toughness, high wear resistance, suitable for most general purpose applications.. Wide Applications: Widely used for drilling stainless steel, aluminum alloy, cast iron, high carbon steel, wood and plastic. Used on electric hand drill, drilling machine and bench drill. Drill metal with high hardness, the rotational speed should be slower than normal drilling.. Reduced Shank: Reduced shank drills expand the size range capacity of a portable drill chuck. Common flute and overall length for minimal adjustment during tool changes. Spiral groove facilitates the export of metal chip, saving time and effort in operation.. Nitride Coating: Black nitride coating adds lubricity for smoother drilling and is more corrosion resistant. Small pockets on the surface of the tool that help to hold coolant near the cutting edge.. Tips: Suitable lubricant is conducive to cutting or cooling, making cutting easier and improving smoothness and dimensional accuracy. When using hand-held electric drill, the recommended speed is 100-1000rpm/min; the larger the drilling diameter, the slower the drilling speed..