Method And Selection Of CNC Machining Holes

There are many methods of machining holes, and commonly used are drilling, reaming, boring, turning, grinding, broaching, honing, rolling, etc.

The following four processing methods are the four most commonly used methods in CNC processing:

1. Drilling hole. Using drill bits to process holes in solid parts of the workpiece is called drilling. It is a rough machining method, the tolerance grade is IT13 ~ IT11, and the surface roughness is about Ra50~12.5μm.
2. Reaming hole. It is to further process the drilled hole to enlarge the bore diameter and improve the accuracy and reduce the surface roughness value. It is semi-finished machining, the tolerance grade is IT11 ~ IT10, and the surface roughness is about Ra12.5~6.3μm.
3. Boring hole. It is a finishing method machining hole, based on the semi-finishing /reaming hole. The tolerance grade is IT9 ~ IT6, and the surface roughness is about Ra3.2~0.2μm.
4. Turning hole. Use the turning tool to process the hole, it can be used as rough machining or finish machining.