The reamer should be applied at the center, that is, the grooves should be cut on the axis or full diameter of the hole.
In Fig. 677 let a represent a reamer and b a segment of an emery wheel.
The operation is to place the reamer into the drilling machine, taking care that it runs true.
It is obvious that in this form the reamer is expanded most at the end.
The reamer is especially desirable for interchangeable work, when all holes must have a smooth finish and be of the same diameter.
The reamer is revolved at high speed and freely supplied with oil.
The reamer thus carries the die with it, the slot in the false face acting as a guide to the die.
The form of center-hole produced by a combination drill and reamer is shown by the lower left-hand view in Fig. 27.
The less you give a reamer to do the longer it will maintain its size.
When a reamer is used in the lathe, the outer end is supported by the tailstock center and should have a deep center-hole.
reamer ream·er (rē'mər)
A rotating tool used to shape or enlarge holes.