Symbol for Exposed Aluminum Surface?

To further 3Doug's correct response, there are symbol modifiers to control not only the average RMS roughness, but the lay of any marks, the maximum and minimum deviation from the average, and what machining and production processes are allowed. Further, use of ANSIY14.5M GD&T symbology would allow you to use the profile of a surface to control the maximum deviation from true form over a given length. GD&T can be your very good friend in such situations.

I've had to deal with these issues when designing metal to metal high pressure seal surfaces.

Thanks everyone for the help. Do you have a link to the ANSIY14.5M GD&T symbology information that you could provide me?

Thanks,

Not a direct link, but my 24th edition of Machinery's Handbook shows and explains the modifying symbology on pages 667 through 679, those page numbers will vary depending on which edition and version of machinery's handbook you might have handy.

Additionally you can buy ANSI/ASME Y14.5M IHS.

I can also suggest that you might find a book titled Geo-Metrics III by Lowell W. Foster useful in understanding how to apply and use GD&T symbology. Mr. Foster was one of the authors of the ASME standard.

Another excellent resource that is available from IHS is their Drawing Requirements Manual.

If you have a good relationship with your vendors, just ask them. If there is a symbol, they probably will send it to you so they don't have to interpret what "exposed surface" means on your drawings.

Good Luck