Some notes from the (now off-line) Shapeoko wiki which may be of interest.
There is at least one company which colour-codes their aluminum:
http://www.westlakemetals.com/opencms/export/westlakemetals/downl/METAL_COLOR_CODESa.pdf
A further consideration is whether or no the material has been heat treated.[https://www.reddit.com/r/Machinists/comments/3k8lgj/are_there_material_pairs_where_one_is_inexpensive/cuxkc89]
- 1000 essentially pure aluminum (99% minimum by weight), can be work hardened
- 1050 not good for machining[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=5267&p=43524#p43524] — report of success w/ single flute endmill: How to cut 1050 aluminium! - #3 by Luke
- 1100 — machinability poor[McMaster-Carr]
- 2000 (copper)
- 2011 — machinability excellent[McMaster-Carr]
- AU4G (2017) is really good at machining : you can take deep passes (~0.3 to 0.5mm) at something around 500 to 800mm/min (20 to 23 ipm). This aluminium will resist to the heat and won’t melt.
- 2024 — very strong and is used a lot in some aerospace applications. It’s ok to work with, I’d say it’s in the middle. It’s not gummy like some other alloys but it doesn’t produce the best finishes and will take a little longer to mill over say 6061-T6[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=4286&p=35383#p35383] If welded, loses its temper and strength.[2024-T3 Aluminum Cutting Question - #8 by mikep]
- Brinell Temper 0 Hardness 47
- Brinell Temper T3 (solution heat treated then cold rolled) Hardness 120
- Brinell Temper T4 Hardness 120
- 3000 (manganese) can be work hardened
- 3003 — machinability poor[McMaster-Carr]
- Brinell Temper 0, Hardness 28
- Brinell Temper H18, Hardness 55.
- 3003 — machinability poor[McMaster-Carr]
- 4000 (silicon)
- 5000 (magnesium)
- 5052 available in sheet. machinability only fair (poor)[McMaster-Carr] Cuts usually look gummy on scrap/drops, easily welded.[2024-T3 Aluminum Cutting Question - #8 by mikep]
- Brinell Temper 0, Hardness 47
- Brinell Temper H34 Hardness 68
- Brinell Temper H38, Hardness 77
- 5086 — machinability poor[McMaster-Carr]
- 5251 not good for machining[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=5267&p=43524#p43524]
- 5456 — machinability poor[McMaster-Carr]
- 5052 available in sheet. machinability only fair (poor)[McMaster-Carr] Cuts usually look gummy on scrap/drops, easily welded.[2024-T3 Aluminum Cutting Question - #8 by mikep]
- 6000 (magnesium and silicon) easily machined
- 6020 — machinability excellent[McMaster-Carr]
- 6060 is really different. It’s much softer and melt faster and stick on the endmill, making it worse. You have to take smaller passes (0.2mm) at high feedrate (around 1000 to 1200 mm/min, or 40 or 47ipm). Using a 1 flute endmill usually give better results.
- 6061 most commonly used aluminum alloy (in the U.S.) — 6061-T6 nice to machine and forgiving. Can be milled without coolant or lubricant if the feed rate, depth of cut, and spindle RPM are set correctly.[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=4286&p=35391] 6082 is very similar and more common in Europe.[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=4827&p=35748#p35727] Thickness for plates is typically Imperial measure.[Nomad beginner help - #6 by DanoInTx]
- Brinell Temper 0, Hardness 30
- Brinell Temper T6, Hardness 95
- 6063
- Brinell Temper T0, Hardness 25
- Brinell Temper T6, Hardness 73
- T651 — contains internal stresses which will deform a machined piece if annealing is attempted.[2024-T3 Aluminum Cutting Question - #8 by mikep]
- 6082 medium strength alloy with excellent corrosion resistance, machines well in T6 and T651 temper[http://www.wilsonsmetals.com/datasheets/Aluminium-Alloy_6082-T6~T651_148.ashx] Thickness for plates is typically metric measure.[Nomad beginner help - #6 by DanoInTx]
- 6101 — machinability poor[McMaster-Carr]
- 7000 (zinc) can reach the highest strengths of any aluminum alloy
- 7075 also gives good results when milling, but is difficult to cut on a Shapeoko[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=4286&p=35391]
- Brinell Temper 0, Hardness 60
- Brinell Temper T6, Hardness 150
- 7075 also gives good results when milling, but is difficult to cut on a Shapeoko[http://www.shapeoko.com/forum/viewtopic.php?f=7&t=4286&p=35391]
- 8000 (other elements)
Brinell Temper:
(Note that these denote a tempering ‘‘process’’ rather than a specific Rockwell hardness[2024-T3 Aluminum Cutting Question - #3 by DanoInTx])
- 0 = Fully annealed (soft)
- H## = Strain hardened (medium)
- T# = Solution treated (hard)