Online Parts Store › Phillips Machine Screw - Flat Head, 5/16"-18 x 2" Image 1 of 1 Phillips Machine Screw - Flat Head, 5/16"-18 x 2" $35.02 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Nylon Insert Locknut - Stainless 1/2-13 $35.14 Phillips Tapping Screws - Flat Head, #8 x 1-1/4" $19.34 Phillips Tapping Screws - Flat Head, #14 x 2" $41.13 Flat Washer, 5/16", .062" Thick, OD 7/8" $21.67 Flat Washer, 3/4", .109" Thick, OD 1-7/8" $47.99