Under Hoffman's direction, J. Chein & Company expanded and prospered, producing many increasingly complicated mechanical toys.
During World War II, J. Chein & Company suspended toy production, instead producing nosecones and tail units for bombs and casings for incendiary devices.
However, as the 1940s drew to a close, they encountered increasing competition from Japanese manufacturers who produced mechanical tin toys for lower prices.
While this provided Chein with a steady demand and often healthy cashflow, it also meant that Woolworth's changing fortunes heavily affected them.
Chein acquired the Learning Aids Group and its lines of educational materials, as well as its Renwal Plastics division.
It utilized a combination of plastic and tin, and a mechanism that used spooled rolls of punched paper with well-known songs programmed onto them.
The device was never financially successful for Chein due to its complexity, high price and the rise to dominance of purely electronic musical instruments.
In the mid-1970s, Chein sold its Renwal division and focused upon manufacturing lithographed sheet steel housewares such as kitchen canister sets and wastebaskets, under the brand Cheinco.