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 Screw - Truss Head #10 x 1" $33.32 Phillips Tapping Screw - Pan Head, #10 x 3/4" $32.06 Socket Set Screw 10-24 x 1/4" $22.63 Phillips Tapping Screws - Oval Head, #12 x 1-1/4" $22.30 Phillips Tapping Screw - Pan Head, #14 x 2" $45.91