How To Mill Slots

Having that leg of the angle iron that you are milling unsupported really isn't the best setup. I'm glad that it worked for you but you should really hold pieces completely.

That formula for calculating spindle speed is wrong too. This is the real formula

(PI * DIA X RPM) / 12 = SFPM

Using your formula it says to run a 5/16 inch cutter at 550 RPM which is only 45 SFPM, less than half the speed you should run. You should mill steel at 100 SFPM or more.

I'll mock up a better setup. Ignore the burn holes in the steel. It is the first piece of scrap angle I found laying around. Anyhow, the hold down on the leg keeps it from fluttering around. Chatter is a bad thing when machining.

.206 slot, you can use a 3/16 end mill & then move it. 13/64 would give you.203. CNC Mill Program Exercise Side Milling Drilling Slot Milling 05007 N001 G71 G90 (Set dimension type mm, set absolute co-ordinate system) N002 G92 X-15.0 Y-15.0 Z0.0 T01 F100 S1200 (Set reference point -15, -15, 0.

How To Mill Slots On Milling Machine

I would first use a 5/16 end mill to cut a central slot clear through the part. From there, it depends on your tolerance for the slot width. Most 3/8 2 and 4 flute end mills will cut oversize slots. A 3 flute end mill will cut closer to the nominal size. Groves and slots - you can mill groves and slots to diferent widths and depths using diferent size end mills T groves - you can mill a T shaped grove in something using a t cutter like the groves on a milling table 12.