Home Forums General Discussion Ask Dr. Peener How to Specify Glass Bead Blast on Aluminum

Good afternoon,

I would like to find out how to properly specify a Glass Bead Blast finish on 6061 Aluminum. The parts are small (fit within a cube 1.5 inches on a side without many sharp corners) and will be Clear Anodized after the blasting. The Glass Beading is being done primarily as a cosmetic item (to get a satin-like appearance) and also to slightly help with epoxy adhesion though I am not counting on that so much. I am willing to try-out some notes and see what "depth" or intensity of peening I get.

I see there is a ton of info about Almen strips and pressure and coverage, but I am having trouble digesting it into a note that I can include on a drawing that goes to a machine shop (or finishing shop).

Do you have any standard note (or note format)? Where can I start in terms of currently used specs. (it looks like an older Mil Spec. has been cancelled without a replacement)? I know I may have to experiment, and I am willing to try-out a batch of parts and see what results come from a given set of notes.

I'll appreciate any help you can offer. Thanks!

Best,
Eric

go with mil-9954-13 size 13 will give u a satin finish and surface roughness will be around 25 to 30
well i dont know your machine of blasting but if it is suction and u use staight long nozzle u can go with 40 psi max 6" off the part and angle 45 degrees
note if the finish is not accepted u need brighter go to mil-9954-10 will help

a follow up i think if u go almen N and thats sure depend on your para and media if they similar to the one i mention before u will have no more than 4 almen N and thats 0.0004N which is 0.00013A for the depth thats depend of the casting machining and in all cases we are takling about 0.0002

I work for a large metal finishing company and we glass bead blast as well as apply anodic coatings. When a customer has a requirement such as this we have them furnish us (or we furnish them) a sample made out of a coupon of the same material, similar to a color standard. When a cosmetic requirement is the spec then the intensity should not matter with the exception of creating a repeatable process.

Wayne

Hi everyone,

Thanks for all your help and input!

We are wrapping-up the drawings now for that project and it was helpful to have the guidance.

Best,
Eric