Online Parts Store › Phillips Machine Screw - Flat Head, 1/4"-20 x 3-1/2" Image 1 of 1 Phillips Machine Screw - Flat Head, 1/4"-20 x 3-1/2" $41.13 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Phillips Tapping Screws - Oval Head, #10 x 2-1/2" $29.85 Phillips Tapping Screw - Pan Head, #8 x 3/4" $19.21 Nylon Flat Washer 3/8", 0.62" Thick, OD 1" $57.19 Phillips Tapping Screw - Pan Head, #14 x 3/4" $49.38 Phillips Tapping Screws - Oval Head, #12 x 3/4" $33.07