Abstract: A cast, low density metal disk for anti-skid devices which has a periphery of sufficiently small width that when it contacts the wet side wall of a tire on a vehicle it spreads the film of water to each side and leaves an essentially dry area of contact between the disk and the tire instead of hydroplaning on it. The periphery preferably is covered with an anti-skid material, e.g., rubber. Chains are pre-turned or twisted in the same direction a tire tends to turn them when rolling over them to avoid further twisting with consequent shortening in use and they are given a non-circular, e.g., square cross section to increase their anti-skid properties. The chains are welded at one end to a steel ring which is removably fastened to the under surface of a disk by bolts.