Best Alum Alloy for engraving

[srmaietta]

Hello all, I am looking to do some cutting and engraving of aluminum plate. These parts are purely decorative, so strength is no issue. I would like to know if there is a "best" or easiest alloy for general machining work. Which would less likely gum up my bits, which is softest etc.. Also, the parts will be anodized.. are there any alloys not sutiable for this?

thanks for your time and any information!

~Steve

[Skeeterd5150]

6061 is the only grade my company uses. But we anodize it all the time. I am pretty sure you can't anodize 5052. Other people will correct me on this if I am wrong but I believe 30 series is the closest thing to pure al you can buy and it is very gummy and will coat your end mills.

[John3]

Steve,

Its as much about the hardness processing (-H or -T number) as it is about the alloy.

1100 Pure aluminum, very soft, not what you want.

2024-T3 High strength, moderate cost, crunchy, machines very nice, can't weld.

3003 & 5052 low cost, usually found in sheet form. A hardness rating of -H32 or greater machines okay.

6061-T6 or 6063-T6 Very common, machines good, low to moderate price, probably your best bet.

7075-T6 High strength,(greater than 1018 cold-rolled-steel), expensive, machines very very nice.

If you were to get some -T0 or -H0 materials you would be very disappointed with them, no matter what the alloy, they would be too soft for easy machining. This can happen to hardened -T6 materials that are heated, they soften to T0 state.

I have had Excellent results anodizing all of the above alloys, just keep in mind that different alloys will take on the anodize and the dye at different rates, giving different colors/finishes for the same processing.

If you are dealing with sheet and have access to a sheetmetal shear, you can gauge how well the material will machine by looking at the surface of a sheared edge. The proportion that cuts (shiny-smooth) and the proportion that breaks (dull-rough) will give you a rough indicator of the material hardness. I'd say if the the break zone is half or greater it will machine okay. If the shiny cut zone is more than half, the material is probably too soft to machine nicely,

John


John

[Geof]

Talk to the people who will be doing your anodizing. Probably you will be best going with 6061 but the inmportant thing is to use something that anodizes well. You can probably work around any problems with the finish you get with the engraving.