Science: Colored Steel

When Oscar Bruno Bach was 18 he made a finely wrought metal Bible cover for Pope Leo XIII's study. A native of Germany but a longtime resident of Manhattan, Oscar B. Bach is, according to the current Iron Age, "probably the foremost metal craftsman of this country." He has done a great deal of impressive metal decoration for public buildings, rich men's homes, ships, mausoleums, world's fairs. Last week bemonocled, pipe-sucking Mr. Bach discussed with newshawks a metallurgical process which he had developed (after years of research), and which not only delivers stainless steel in a variety of colors but also increases greatly the corrosion resistance of inexpensive chrome steel.

Metallurgists have tried to produce colored stainless steel for years. One of the first patents, issued to Columbia University's crack Electrochemist Colin Garfield Fink in 1933, has never been industrially developed. Researchers of Allegheny-Ludlum Steel Corp. are reported to have hit on a promising technique, but they are keeping it under wraps for the present. Mr. Bach, skeptical of patent protection, kept mum about his method for quite a while.

In the Bach process, the steel is first "pickled" (cleaned with acid), then coated with colorless chemicals (formula undisclosed) and heated. The coated steel turns black, gold, bronze, purple, blue, red or green, and the color becomes an integral part of the surface. The treatment increases the corrosion resistance of 6% chrome steel (16¾¢ per Ib.) almost to that of high-grade chrome-nickel stainless steel (34¢ per lb.). Said Iron Age: "The increase in corrosion resistance, in part verified by at least several disinterested laboratories, is astonishing." Last week Mr. Bach declared that use of cheap steel, thus colored and corrosion-proofed would greatly reduce the cost of prefabricated houses.