Does any one know any significant differences between 6061 aluminum and 6063 aluminum. I have done the research and am unable to find a significant difference, can any help me out.
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Modulus, as with most aluminum alloys, is approximately the same. However, quoting Mcmaster, 6061 T6 has approximately 4 times higher yield strength- ~40,000 psi vs 16,000 psi for 6063. So depending on the application, a switch may or may not make a difference. If you need stiffness, it wonât really make a difference. If itâs yield youâre after, such as in a threaded rod, pick the 6061.
6061 is also easier to machine from my understanding. It doesnât âmushâ up as one of our mentors said.
6061 is both stronger and easier to machine because it wont clog the endmill or whatever you are using as easily as 6063 we always use 6061.
6061-T6 yield is about 39 ksi, versus 31 ksi for 6063-T6. So those McMaster numbers are comparing apples to orange popsicles.
As far as machinability, I donât think the difference is incredibly large. However, 6063 is mostly common for more complex extruded shapes anyways, so youâre less likely to be doing large amounts of machining on it in the first place.
There is some confusion here about the two alloys. Hopefully this will benefit others as well.
â6063â and â6061â are not sufficient descriptions of the materials in question. To know the specific differences, you need to know the specific heat treatment/tempering process of the alloy.
If you compare 6063-T6 and 6061-T6 you will find that their properties are similar with 6063 having a slightly lesser Ultimate Tensile and Yield Strengths. However, if you look at mcmaster, I can only assume they are selling a 6063-T4 and 6061-T6. If you compare them, then yes, 6063 has a considerably lesser ultimate tensile and yield strength. However, for 6063 the % elongation almost doubles, from 12% to 22%.
The machnining differences have everything to do with the heat treatment as well. The T6 alloy will probably machine better than the softer T4.
Edit: Seems that kevin posted part of what I was getting at before I was finished writing. 
I will leave it as is with a little extra explanation.
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this pretty pretty much copy and pasted from a Mcmasters data sheet but whatever, the information is all there.
An exclent source for materials data is www.matweb.com. They offer data on a wide range of materials, and information on different alloys, heat treatments and even specific dimensions of samples.
The relevant pages for the two alloys, both with a T6 treatment.
Of course, its all refrence data, and they keep a disclaimer against using that data for design. Ideally, you would do your own testing with samples of the material as it comes from the supplier. For FIRST purposes, its fine to use handbook data like this.
Testing methods vary from one source to another. The important thing is to pick a reputable source and stick to it. I think there are a couple âmachinist handbooksâ out there that would probably have this kinda of data.
I need to throw in my warning here, as I do in every post about 6000 series aluminum. If you weld it, the yield strength goes from about 39 ksi to about 11 ksi in the heat affected zone (usually within about 1 inch of the weld).