I have never seen a hillside washer spec'd out.
I would give Portland Bolt a call as they are normally on top of most specifications.

http://www.portlandbolt.com/products/washers/hillside_washer.html?gclid=CLfh78WapZ8CFQMNDQodO3nXcg

Thank you for the comment.
I have already looked at the Portland Bolt site as well as the Fastenal site. The Fastenal site listed an ASTM F48. This is a dead standard and was not for hillside washeres. The issue with my need is that since this material is going into a nuclear NAQ-1 site I have to have an industary reconized standard to didicate the material too.
Any thoughts?  

If all you are looking for is a washer that is produced on a slight bevel (15 degrees or so) ASTM F436 has an option for that.
If you are looking for the cast washers that retain a diagonal brace rod and bear on the back of the beam or column web, there is no specific ASTM standard for those washers.  The shapes are proprietary to the various manufacturers.  There would be ASTM standards available for the material that is used to form the washers.   ASTM A27, A47, A48, and A148 are all ASTM casting standards that might be deemed to apply depending on the material used in the casting.
I would suggest having your own specification that mandates specific proof and ultimate loads that the casting must meet.  Testing protocols could be similar to ASTM F1145 for turnbuckles.

ajh1;

Thanks for the information. It is exactly what I needed. From here I will use the ASTMs you lead me too and develop a didication plan that I can use (with a 3rd party testing firm) to qualify this hillside washers.