Online Parts Store › Phillips Machine Screw - Oval Head, 5/16"-18 x 2-1/2" Image 1 of 1 Phillips Machine Screw - Oval Head, 5/16"-18 x 2-1/2" $20.09 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 Screws - Flat Head, #14 x 1" $45.79 Lock Washer, 7/16" $32.06 Phillips Tapping Screw - Truss Head #10 x 3/4" $31.18 Phillips Tapping Screw - Pan Head, #10 x 1-1/2" $36.40