Online Parts Store › Phillips Machine Screw - Flat Head, 1/4"-20 x 4" Image 1 of 1 Phillips Machine Screw - Flat Head, 1/4"-20 x 4" $41.25 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Phillips Self Drilling Screw - Pan Head #10 x 3/4" $36.40 Nylon Insert Locknut - Stainless 5/16-24 $46.35 Seachoice 01011 Lock Washer ,5/16" $31.68 Stainless Fender Washer #6, .050" Thick, OD 3/4" $19.71 Nylon Insert Locknut - Stainless 5/16-18 $18.01