8 Inch Adhesive Back Silicon Carbide Sanding Discs, 5 Pack

Just received my sanding disks and belts. All looks great. Quick service and nice website. I am optimistic these will be great products.

I'm Mr QA Mgr for an iron foundry in Minnesota. With ductile iron, S.O.P.'s are to polish a sample to view the graphite nodules that should be there after performing the proper treatment of the iron to cause it to become ductile iron. I thought in the past we used to get 600 gfn 8" disc tried some, including Red Labels which were on the higher end of Quality, but under the microscope the samples still had heavy grooves in the metal surface making it difficult to view the nodules. I then tried an 800 gfn black silicon disc I got from Red Label. This was better, but not good. As the experts, do you have a recommendation of a material and gfn that could polish iron to somewhat of a mirror finish without water and wouldn't break the bank?

This is not the first time I try your products, they are above the excellent, but my only admiration is that you do not ship internationally only