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How to Spec and Quantify a Matte Finish

Is there a Standard or some other spec I can call out on a drawing for a Matte finish on SS? My suppliers are told to fabricate SS parts and them to apply a matte finish. Well, that is a little subjective plus my incoming inspectors don't have a standard to inspect to. So the end result is having varying degrees of "matte" finish.

Bill Porter
Electronics Mfg. - Dallas, Texas
2006

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First of two simultaneous responses --

Depending on the roughness you desire, there is a well known surface finish standard from the SPE that includes several codes which are matte finishes produced by sandpaper and abrasive blasting with different size and quality media. You can buy some of these plates for your inspectors and your supplier can do the same. We always have some available since we constantly have similar problems. Let us know if we can help.

Guillermo Marrufo
Monterrey, NL, Mexico
2006

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Second of two simultaneous responses --

The old catch 22 question. About the only thing you can be sure of is the surface finish in a known standard of Ra or Rms. If it were a brushed finish, you could call out the wire brush required. For a matte finish you can call out either a blast finsh and the specific media or for mass finishing you can call out the specific size, shape, and composition of the media to be used. Even given this info, your inspectors will not be able to verify these finishes either unless they see it in operation.

AF Kenton
retired business owner - Hatboro, Pennsylvania
2006

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2006

Thanks for the input. Guillermo, excuse my ignorance but what does SPE stand for? I'd like to see what plates they have to offer.

I guess I figured there would be a Mil spec for this. I'm also needing something to spec "satin" finish.

We do call out the type of media to use but depending on the machine and parameters used the operator can make different finishes using the same media.

Bill Porter
- Dallas, Texas

SPE stands for Society of Plastics Engineers. We belong to it and have some of those plates manufactured according to their specs. We have sold some to our customers in the field of plastic injection molds. Let us know if we can help.

Guillermo Marrufo
Monterrey, NL, Mexico
2006