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Aluminum Speeds and Feeds

Guide · Updated October 28, 2026

Aluminum machines fast, but the limit is usually chip evacuation and built-up edge, not the tool. Use these as shop starting values, then adjust by sound, chip color and finish. For the formulas behind them, see the general guides linked below.

Hold size in aluminum

Aluminum grows about 13 millionths per inch per °F; check parts at room temperature with a mic verified against gage blocks. The free Gage Block Calculator builds the stack.

Skip the math: free speeds & feeds calculator turns these SFM and chip loads into RPM and IPM.

Step by step

Identify the alloy: 6061-T6 and 7075-T6 machine well; cast and soft alloys like 1100 gum up more.
Pick the tool: Use sharp, polished, uncoated or ZrB2/DLC carbide with 2 or 3 flutes for milling.
Set surface speed: Start around 800–1,500 SFM with carbide (much less with HSS, about 250–600 SFM), limited by spindle RPM.
Set chip load: For a 1/2 in carbide end mill start around 0.003–0.005 in per tooth in slotting.
Coolant: Use flood coolant or mist plus air to clear chips and stop built-up edge.
Test cut: Run a short cut and listen; adjust feed before speed if it rubs or chatters.

Starting values table

Milling, carbide: 800–1,500+ SFM; chip load per tooth about 0.001–0.002 in (1/8 in tool), 0.002–0.004 in (1/4 in), 0.003–0.006 in (1/2 in).
Milling, HSS: 250–600 SFM, roughly half the carbide chip load.
Turning, carbide: 600–1,500 SFM, feed 0.005–0.015 in/rev roughing, 0.002–0.006 in/rev finishing, with a sharp, positive, polished insert.
Drilling, HSS: 200–300 SFM, feed about 0.002 in/rev for 1/8 in up to 0.008 in/rev for 1/2 in; peck deep holes.

Worked example

A 1/2 in 3-flute carbide end mill at 1,000 SFM: RPM = 3.82 × 1,000 ÷ 0.5 ≈ 7,640 RPM. On a 4,000 RPM mill, run 4,000 RPM. Feed = 4,000 × 3 × 0.004 ≈ 48 IPM. Keep the chip load, not the SFM, when you are RPM-limited; otherwise the tool rubs.

Built-up edge and chip welding

Aluminum welding to the cutting edge leaves a torn finish and can snap small tools. Fix it with a sharper, polished tool, more coolant or air blast, fewer flutes for chip room, and a higher feed per tooth rather than slowing down.

Tips

Formulas: feeds and speeds basics.
Milling detail: milling speeds and feeds.
Turning detail: turning speeds and feeds.
Drilling detail: drilling speeds and feeds.

FAQ

What SFM for aluminum?

Start around 800–1,500 SFM with carbide and 250–600 SFM with HSS, then adjust.

How many flutes for aluminum?

Two or three flutes give the chip room aluminum needs.

Why does aluminum stick to my end mill?

Built-up edge from a dull or coated tool, low feed or poor chip clearing; use a polished tool, air or coolant and more chip load.

Can you machine aluminum dry?

Light cuts can run with air blast, but mist or flood coolant stops chip welding on heavier cuts.

Is 7075 harder to machine than 6061?

7075 is stronger but usually machines cleaner with less gumming; similar starting speeds work.

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