Reamer Speed is measured by the rate at which the outside diameter of the tool moves in relation to the work piece. This speed is known as Surface Feet Per Minute (SFM) and is shown in the table below. The formula used to convert SFM to Revolutions Per Minute (RPM) is:


The speeds shown in this table are a generalization and it is recommended that the user start at the lower end of the range and build up to the maximum after trial indicates this is possible.

Material	Hardness Rc	Speed SFM	Speed RPM
Steel
Mild Steel		215
Plain Carbon		215
Alloyed	<30	175
Alloyed (Hardened & Tempered)	30-38	145
Alloyed (Hardened & Tempered)	38-45	110
Cast Iron
Cast Iron		200
Titanium
Alloys (Annealed)		82
Alloys (Treated), Inconel		48
Aluminum – Magnesium
Aluminium		420
Magnesium		420

Recommended Feeds For Reaming

Reamer Diameter	Feed (Inch/Revolution)
Up To 1/16 1/16 – 1/8 1/8 – 1/4 1/4 – 1/2 1/2 – 1" 1" +	.001 – .003 .002 – .006 .004 – .010 .006 – .015 .010 – .030 .020 – .050