Constructed of high quality corrosion-resistant galvanized finish for long-term use and durability against tough environments and conditions Highly compatible with screws, nuts and bolts of same sizes and feature solid bearing surface to prevent nut/bolt head from tearing through material Designed to spread the load of a screwed fastening and prevent loosening in industrial, shop, automotive and home appliances Includes sturdy plastic case for easy storage and organization of the 12 variations of commonly used lock and flat washers Set comes with the following quantity of sizes: 50 x #6 Lock Washer, 40 x #8 Lock Washer, 30 x #10 Lock Washer, 25 x 1/4' Lock Washer, 15 x 5/16' Lock Washer, 15 x 3/8' Lock Washer, 50 x #6 Flat Washer, 40 x #8 Flat Washer, 30 x #10 Flat Washer, 25 x 1/4' Flat Washer, 15 x 5/16' Flat Washer, 15 x 3/8' Flat Washer