Set screw, STAINLESS A2, 11mm hex head, M7 x 1.00, 35mm long, Sold per SINGLE screw.

If you use stainless steel in conjunction with carbon steel (most regular steel) remember that water is the electrolyte which will permit the stainless to 'rob' electrons from the regular steel, weaken it and cause it to rust very quickly - only the use of a permanent full bodied setting rustproofing agent will stop the regular steel becoming sacrificial.