- Joined
- Dec 14, 2019
- Location
- Pretoria, South Africa
I know that the above advice is commonly repeated...... Straight flute reamers are pretty cheap and will do most of the applications except for interrupted cuts (keyways usually). Spiral is than needed.
Those are machine reamers, and do not cut on the flutes, they cut (only) on the chamfer at the end, they are ground cylindrical on the OD and only relieved on the flutes to within perhaps 1/32 of the edge of the flutes, thus, a machine reamer can be sharpened many times and shortened accordingly, depending if it needs to bottom in a hole.If you are purchasing the reamers for the first time, if the price is close, get the longer reamer if you can. Straight flute reamers are pretty cheap and will do most of the applications except for interrupted cuts (keyways usually). Spiral is than needed. Most of my holes are 1/4"-3/4" deep. But now I am making bearings for steam engines and the flutes are long enough for that without further purchase. If you are going to do high volume in a particular size, get the shortest/cheapest one you can. Reamers can be resharpened but it is not worth the trouble and it alters the size.
Charles