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 Phillips Tapping Screw - Pan Head, #8 x 1/2" $13.86 Square Tapping Screw - Oval Head #10 x 1-1/4" $57.05 Phillips Tapping Screws - Flat Head, #8 x 1/2" $12.41 Stainless Fender Washer #10, .062" Thick, OD 1" $48.06 Nylon Flat Washer #6, 0.32" Thick, OD 3/8" $17.45