What are the main factors affecting twist drill drilling accuracy

Greater impact on the accuracy of the hole were the depth of cut and feed rate, twist drill bit life for a greater impact of the cutting depth and cutting speed. Therefore, they should control the depth of cut, cutting speed and feed rate. Avoid large amount of cutting, reduce the heat, to avoid shock and vibration, eliminate work hardening and improve processing quality and extend bit life. Pre-drilling should prevent more chilled layer, otherwise it will increase the load and wear fine drilling drill holes.
    Twist drill will wear out after repeated use, and affect the accuracy of the aperture. Drill two cutting edges need grinding symmetrical as possible. Drill as a complex tool, required to ensure greater durability, and put forward certain restrictions corner wear amount as blunt standard.
    Twist drills and reamers comparison, there are similarities. If the two main cutting edge and the secondary cutting edge minor cutting edge spiral, and with a blade and chamfering can increase cutting stability. As long as the drill cutting angle and surface roughness of the hinge edge reference requirements to improve and improve. Basically have a similar hinge edge conditions.
Due to drill precision holes (twist drill reaming is milled by the change in the basis of the existing drill holes for further processing by reaming drill a hole finishing operations, referred to drilling fine holes) is finishing its accuracy and the surface roughness is higher, and the cutting load is small, it should choose to lubricate-based coolant.