What are the key points to pay attention to when drilling a small carbide drill?

When using a small carbide drill to drill, due to the low bending strength of the cemented carbide and the large torque during drilling, the resulting high temperature causes the thermal expansion and contraction of the workpiece, which will easily cause the drill to break in the hole and cause the Trouble with the drill bit may make the work piece a waste. For this reason, pay attention to:

1. When drilling different materials, choose the corresponding cutting speed, not too high or too low. Such as drilling hardened steel should choose vc=30m/min or so. The cutting amount is suitable for drilling brisk and continuous chipping.

2. When the strength of the drill point permits, the width of the chisel edge should be reduced to reduce the axial force.

3. When drilling, the drill should be retracted frequently to avoid thermal expansion and contraction of the workpiece. When the drill is deep, the diameter of the upper part of the hole shrinks and there are too many chips, which will jam and twist the drill.

4. When drilling materials with severe surface hardening, the feed should be uniform, and try to avoid the friction on the cutting surface due to the stop of the cutting tool, which will cause more serious hardening and aggravate the wear of the drill.

5. The cutting fluid should be selected according to different workpiece materials to increase lubrication. But there must be sufficient supply, not from time to time.