1. Drilling holes(drilling machine)
Pay attention to below items:
1) Feed drilling bit towards face, the power can’t be too big, in case to break drilling bit and hole misregistration.
2) If the chip can be easy to removed, it needs to feed bit back to remove chips.
3) Cooling liquid is needed when drill steel material
4) Take 2-3 times to drill holes with diameter large than 30mm(reduce resistance)
5) When hole is about to drill through, decrease feed of drilling bit.
2. Turning holes(lathe)
It is a kind of finish machining for holes, and also a common processing of lathe
1) After rough turning, before finish turning, for thin wall workpiece, it is better to loose chuck a little and then tight it up lightly.
2) Before turning hole, check the length of turning tool chunk is long enough and mark it
3) While turning Counterbore, turning tool should has an angle against surface of workpiece
4) There is no need to add cooling liquid if it is hard alloy turning tool.
3. Reaming holes
The reason the reaming holes have good quality: low speed cutting, cutting edge is not easy to build up under not high temperature. Change of tool’s size change tinily and there is no vibration of cutting.