What is the reason for the deep hole processing aperture reduction?

Deep hole processing is known to be a difficult processing project. So why does deep hole machining reduce the diameter of the inner hole?

The design value of the outer diameter of the reamer is too small;
Cutting speed is too low;
The feed rate is too large;
The main angle of the reamer is too small;
The cutting fluid selection is not suitable;
When the sharpening is performed, the worn portion of the reamer is not worn off, and the elastic recovery reduces the aperture;
When reaming steel parts, the margin is too large or the reamer is not sharp, and it is easy to produce elastic recovery, so that the aperture is reduced and the inner hole is not round, and the aperture is unqualified.

Replace the outer diameter of the reamer;
Properly increase the cutting speed;
Properly reduce the feed rate;
Appropriately increase the lead angle;
Select an oily cutting fluid with good lubrication performance;
Regularly exchange the reamer to correctly sharpen the cutting part of the reamer;
When designing the size of the reamer, the above factors should be considered, or the value should be taken according to the actual situation;
For experimental cutting, take the appropriate margin and sharpen the reamer.