Online Parts Store › Nylon Insert Locknut - Stainless 4-40 Image 1 of 1 Nylon Insert Locknut - Stainless 4-40 $21.16 18-8 Stainless Steel. Add To Cart Added! 18-8 Stainless Steel. You Might Also Like Carriage Bolt, 1/2"-13 x 3" $92.78 Phillips Tapping Screw - Pan Head, #14 x 1-1/4" $33.19 Seachoice 18-8 Stainless Steel Wing Nuts, 1/4-20 Size, Pack of 100 $110.41 Flat Washer, #4, .032" Thick, OD 5/16" $6.74 Phillips Tapping Screws - Flat Head, #8 x 5/8" $12.41