Online Parts Store › Nylon Insert Locknut - Stainless 1/4-20 Image 1 of 1 Nylon Insert Locknut - Stainless 1/4-20 $27.84 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Stainless Countersunk Finishing Washer, #4 $13.29 Square Tapping Screw - Flat Head,#10 x 2" $31.61 Square Tapping Screw - Flat Head,#8 x 1" $27.12 Phillips Tapping Screws - Flat Head, #8 x 3/8" $11.90 Flat Washer, 5/16", .062" Thick, OD 7/8" $52.44