proeguy-
There are some military standards for metric fasteners but to find a source with reasonable minimum buys and prices may be problematic.
There does exist an unofficial but widely-recognized part numbering that clearly calls out the size, the material type, and the governing spec.
If there was an M4X12 socket head cap screw defined in ISO9138 (this is a purely fictional number I am using just for purpose of explanation) and if the standard defined two grades of stainless steel, say A2 for a low strength grade and A4 for a high strength grade then the part number, then one valid part number is M4X12ISO9138-A4. This part number nails everything down completely within the confines of the spec. Vendors will sell screws to you using this part number and will provide you with certs to the spec as well. This has been my experience. If a vendor won't sell screws to you using this method then I suggest finding a new vendor.
Tunalover
Tunalover