Another benefit of lead-free steel: Its cutting residue (top) is more granular and easy to handle than that from conventional steel (bottom). Mitsubishi Steel has developed free-machining steel that eliminates a nagging environmental headache: lead. People have been filling up at the gas station with unleaded gasoline for decades. And manufacturers have been racing in recent years to adopt alternatives to lead-containing solder. Now, getting the lead out of steel has become a global cause.    Steel makers have good reason to put lead into their steel for machining. The melting point of lead is much lower than that of steel. So the lead leaks out of the steel when the friction of machining raises the temperature. It acts as a lubricant between the cutting tool and the steel. That extends the life of the cutting tools. It also makes the steel easier to cut.    Mitsubishi Steel has discovered a way to use sulfur and niobium instead of lead to improve the machinability of steel. Its unleaded steel provides the strength and durability required in such demanding applications as automobile crankshafts and connecting rods. The steel also is applicable to a full range of mechanical components in nonautomotive applications.

Thanks to Dai Nippon Toryo, this bridge is unleaded, unchromed and uncorroded. Dai Nippon Toryo also is getting the lead out of its products. It's eliminating the chrome, too. Lead and chrome are useful in improving paint finish, and they appear in some common pigments. Unfortunately, the lead- or chrome-containing pigments are extremely toxic. So manufacturers have been seeking safer alternatives. That search is gaining momentum in Japan as national government and local authorities begin mandating lead- and chrome-free paints and coatings in public works projects.    Engineers at Dai Nippon Toryo have come up with phosphate-based coatings that protect surfaces from corrosion reliably without using lead or chrome. They continue working to replace all toxic materials with benign alternatives.

They're gonna make Japan's sky bluer. Nippon Oil is doing its part to help automakers make their cars, trucks and buses run more cleanly. Technology has come a long way in reducing noxious emissions from automotive engines. A lot of the progress has been in the now-familiar catalytic systems for neutralizing would-be pollutants. However, a big obstacle to further progress in cleaning up automotive emissions is the sulfur in gasoline.    The sulfur in gasoline diminishes the effectiveness of catalytic converters and therefore causes an increase in noxious emissions. Combustion oxidizes the fuel-borne sulfur, and the sulfur oxides compete with other pollutants for space on the catalytic surface.    Governments and automakers have been calling on the oil industry for years to provide lower-sulfur fuel. Japan is a world leader in supplying motor vehicles with sulfur-clean fuel. The sulfur content of gasoline in Japan is about 100 parts per million, compared with an average of nearly 300 parts per million in the United States.    Now, Nippon Oil is taking Japan a step further toward cleaner motor transport. Earlier this year, it began supplying gasoline that has a sulfur content of less than 50 parts per million. The gasoline, which is available through dozens of Tokyo gas stations, heralds a new phase in the struggle against pollution.