Online Parts Store › Phillips Machine Screw - Flat Head, 5/16"-18 x 1-1/4" Image 1 of 1 Phillips Machine Screw - Flat Head, 5/16"-18 x 1-1/4" $28.28 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Phillips Tapping Screw - Pan Head, #10 x 3" $37.54 Phillips Wood Screw - Flat Head, #14 x 3" $73.50 Seachoice 01006 Lock Washer, #8 $15.43 Stainless External Tooth Lock Washer 1/4" $19.78 Stainless Cotter Pin 3/32" x 1" $46.14