Heavy Duty 3/8” thick case-hardened steel. For tractors, backhoes, graders, loaders, scrapers and plows. Case hardened in accordance with ASTM E18 Standards. Snow Chains spacing is defined as the number of side chain links skipped between cross chains. A 4-link tire chain, cross chains occur every 4th side chain link. V-bar is helpful on hills, ice and hard packed conditions. V - Bar or Ice Bar chains are not recommended on pavement since they can damage the surface if the tires begin to spin.