Machining Standards - cleanup cut on base material

[sbrats]

For sake of argument I am buying a piece of 6" aluminum plate against AMS-QQ-A-250/11 - in reality what is the real usable thickness of material that can be 'used' in a design? - or worded in another way - forgetting about flatness etc.. how much cleanup it normally taken per side to accounting for the material manufacturing process? Is this a % of the thickness that could be applied to all plate products.
So think of it this way, as a designer I am selecting material sizes as part of the design process. Say I need a finished value of 1/2" - I certainly wouldn't buy a piece of 1/2" plate - because I would never meet tolerance because the plate needs to be cleaned up - but maybe I could change the design to have a finished value of .450" and meet tolerance because I know that I need say .010 per side cleanup. Now if I really needed .50 I could start with a piece of 3/4" but think of the additional machining required (but then it could be a cost trade off etc etc...)
Is there a spec somewhere?

Thanks for listening..

 

[TVP]

There should be a standard referenced in SAE AMS-QQ-A-250/11 that covers allowable dimensional variation, also known as "standard tolerances". I don't have it in front of me, but it is likely ANSI H35.2. The individual tolerances for thickness, lateral bow, and flatness will all affect the usable thickness or whatever you want to refer to it as. The tolerances vary with thickness and width. A 0.5" 6061 plate that is < 39.37" will have a thickness tolerance of + 0.023", lateral bow tolerance of 0.032", and flatness tolerance of 0.25" (longitudinal) or 0.375" (transverse).

 

[unclesyd]

Given the numbers by TVP you can easily beat them or match them in Al plate. Here are 3 companies that supply Al plate in various shapes forms and fashion. I would contact these companies, not use just the capabilities shown on the webpage.

I have used all these companies and the product was as good as or better than advertised.

http://www.tcialuminum.com/index.html

http://www.tciprecision.com/machine-ready-blanks/capabilities

http://www.dixmetals.com/index.htm