# Speeds for Aluminum



## NRG 4055 (Sep 11, 2013)

At what RPM and what speed rate should we use to cut 1/4 inch aluminum with a 3 flute solid carbide bit.


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## Quillman (Aug 16, 2010)

Right through its thickness?? Not safe in one shot at any speed.
Fractional thickness cut? Possible but only if the side cut is spartan.
You need to be more specific about the cut and cutter diameter.
These cuttings, whilst all have seen a router bit, were all cut at 20-22KRPM with different cutters.
However, everyone of these cuts were fixtured for very modest slices of <.008"/pass.
It may sound painfully slow, but they were hit coming & going so one pass is about 1/64".


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## rwl7532 (Sep 8, 2011)

Quillman said:


> Right through its thickness?? Not safe in one shot at any speed.
> Fractional thickness cut? Possible but only if the side cut is spartan.
> You need to be more specific about the cut and cutter diameter.
> These cuttings, whilst all have seen a router bit, were all cut at 20-22KRPM with different cutters.
> ...


So even less than one INCRA jig notch.


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## Quillman (Aug 16, 2010)

I think they used to be 1/64 - 1/32.
For a side cut in a one direction pass: Too much.


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## rwl7532 (Sep 8, 2011)

Quillman said:


> I think they used to be 1/64 - 1/32.
> For a side cut in a one direction pass: Too much.


1/32nd is the imperial increment INCRA uses. So spacers are needed. Thin like a sheet of paper or so.


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## rwbaker (Feb 25, 2010)

If you cutting Aluminum shapes then why not a scroll saw?

Baker


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## Dr Neon (Apr 15, 2010)

Apples and Oranges, here. With an end mill bit, carbide, 1/32" (.03125") at a time, horizontally, works fine with 5000 series and above. Inches per second/minute depends on the diameter of the bit. For an edge cut, the full thickness of 1/4" material is most easily removed with a multi-edged bit. 2-3-4 cutting edges. The larger, and the most number of blades, will cut the fastest and smoothest. 3000 series and below are not recommended for router cutting. The teeth gall the material, which results in broken bits.


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