Importance of setting drill press RPM

[LCHIEN]

repost from 2006 post I made. 3/8" drill at various speeds, 3/4" pine. feed rate adequate for cutting and removal.
Table saw Cut thru row of holes after drilling.


Select the correct speed for clean holes. RPM for drill press depends on material, bit diameter and bit type.

Drill press speed chart here:
https://www.woodmagazine.com/woodwor...ss-speed-chart

Original post
https://www.sawdustzone.org/forum/di...ct-drill-speed

How many of you actually ever change the drill press speed?

Getting Technical - the ideal cutting speed is the linear rate of the cutter on the material. it differs for different material hardness and machinability. Consider that for a given material as the bit diameter increases the linear cutting speed gets higher because of the radius increase. The general rule of thumb for a given material and type of bit is that the ideal RPM goes down with increasing diameter to keep the linear cutting speed at the edges more or less in the desired range.

The linear speed at the cutting edge is of course Dia (inches) x Pi x RPM in inches per minute.

[leehljp]

Thanks Loring. I have used this example on the pen turning forum a several times. For some reason, a few think slower drilling and turning make for smoother cuts.

[cwsmith]

Thanks for the informative post Loring,

Actually seeing the 'cut' example is very illustrative of the difference it makes! I have a drill speed guide posted on the wall behind my Ridgid floor-standing drill press , and keep a magnetic label on the front to indicate it's present belt setting.

CWS