Rust never sleeps. That's why engineers at U.S. Tsubaki Inc., Wheeling, Ill. (www.ustsubaki.com), put extra protection on its new Neptune Chain. It features a top coat that protects against impacts and corrosive agents, and a zinc-based coating that extends corrosion protection and prevents oxidation from reaching the chain's carbon-steel core. Zinc is applied using a low-temperature process with no acid wash, so chain strength and wear life are not sacrificed. It is the only rust-resistant chain containing no chromium, according to the company. This means it can't expose personnel to hexavalent chromium, a known carcinogen that may be harmful when inhaled or absorbed, and is being phased out of the automotive, construction, and steel industries. In tests involving water, seawater, and outdoor conditions, the chain lasted ten times longer than nickel-plated chain.