Online Parts Store › Stainless Countersunk Finishing Washer, #5/16 Image 1 of 1 Stainless Countersunk Finishing Washer, #5/16 $22.42 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Flat Washer, 7/16", .062" Thick, OD 1-1/8" $27.80 Phillips Tapping Screw - Truss Head #8 x 3/4" $17.19 Square Tapping Screw - Oval Head #8 x 1-1/2" $54.12 Phillips Tapping Screws - Oval Head, #10 x 3/4" $23.24 Stainless Cotter Pin 1/8" x 1-1/2" $55.55