1. Strengthen the guide to reduce hole deviation
　　(1) appropriate to increase the edge angle drill, drilling can be reduced radial force, help to reduce wear and reduce the guide block skewness of the borehole.
　　(2) changing the drill angle and tooth width, must ensure that the radial force is always pressed against the guide block, never allow deviation from the guide block direction. Radial force is neither too small nor too big. Radial force is too small will weaken the drill guide, prone to vibration; much radial force easily broken film guide block, the guide block wear is rapid.
　　(3) improve the accuracy of the guide sleeve or guide holes to strengthen the guiding role.
2. Location accuracy of parts controlled processing systems to improve the dimensional accuracy of drilling
　　(1) controls the spindle, the guide sleeve (or guide hole) and coupling the three hole concentricity error must be less than 0.03mm
　　(2) strict control of the guide sleeve and drill pilot holes or gaps, and to maximize the use of the guide sleeve rotatably to ensure adherence drill cuttings.
3. Stable drilling drilling to reduce surface roughness
　　(1) the outer surface of the bit teeth secondary cutting edge and a guide block drill roughness roughness should be less than 2-3, preferably Bei light oil stone fruit and secondary edge transition edges.
　　(2) the choice of appropriate and efficient cooling liquid cooling. Selection cooling effect, strong anti-adhesion properties of deep-hole drilling fluid, and to ensure adequate supply of cooling liquid is smooth chip removal, heat quickly. In addition, the coolant must be well filtered to reduce the surface roughness borehole.
　　(3) the guide block adoption shadow good wear resistance, adhesion resistance alloys to reduce cutting of adhesion.