How To Mill Slots In Steel
jmarkwolf
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- Nov 9, 2012
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I'm milling some 3/8' x 7/16' slots in mild steel for tool holders. The slots are 2.25' long and I'm using a mill-drill and a 3/8' end mill. Perhaps I'm just 'chicken' but on the first cut, which is the full 3/8' wide, I'm taking cuts of 0.033' deep each pass and it's taking about 12 passes to get to the bottom.
How To Mill A Slot In Steel
Much of my home-shop machining experience has been aluminum (experimental aircraft applications). I'm advancing into the 'hard stuff' now (mild steel).
I never paid much attention to how many flutes my end mills had, I just purchased what the local Production Tool Supply had on hand. The aluminum didn't seem to care.
I recently needed to cut a 1 -1/16in diameter counter bore 0.125in deep in some angle iron, to accommodate flush mounting some weld studs I fabricated. The only end mill I had was a 2-flute.
It did the job for me, but it 'chattered' to beat the band, even with flooding with oil. It seemed to like a faster feed rate as well.
Can anyone advise 'when and why' to use end mills with various numbers of flutes?
I never paid much attention to how many flutes my end mills had, I just purchased what the local Production Tool Supply had on hand. The aluminum didn't seem to care.
I recently needed to cut a 1 -1/16in diameter counter bore 0.125in deep in some angle iron, to accommodate flush mounting some weld studs I fabricated. The only end mill I had was a 2-flute.
It did the job for me, but it 'chattered' to beat the band, even with flooding with oil. It seemed to like a faster feed rate as well.
Can anyone advise 'when and why' to use end mills with various numbers of flutes?
How To Mill Slots In Steel Shell
How To Mill Slots In Steel Toe Shoes
- Drill a start hole at the end of the slot with a drill bit,7/16 is a good size for a 1/2' slot.Run the mill at 1/2 the speed you would for mild steel,about 250 rpm. Plunge all the way trough and mill it in one pass running about.002' chipload per flute.Brush on thread cutting oil forget all the floozy perfume.
- Sandia has become proficient at milling slots between 20 and 30 microns wide in materials including aluminum, brass and 4340 steel. A typical depth of cut is 1 micron. One test in aluminum using a carbide, two-edge, 22-micron-diameter end mill at 1-micron depth of cut and 18,000 rpm showed that this tool could perform effectively at feed rates.