Online Parts Store › Phillips Machine Screw - Flat Head, 3/8"-16 x 4" Image 1 of 1 Phillips Machine Screw - Flat Head, 3/8"-16 x 4" $47.17 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Phillips Tapping Screw - Truss Head #8 x 1/2" $18.52 Flat Washer, 1/2", .078" Thick, OD 1-3/8" $74.51 Phillips Tapping Screw - Pan Head, #8 x 1-1/4" $27.71 Phillips Tapping Screw - Pan Head, #12 x 1" $40.94 Phillips Tapping Screws - Flat Head, #6 x 1" $11.21