By the end of 1974, when the Concrete Reinforcing Steel Institute completes its 50th year in operation, it will have distributed and estimated one million technical publications to users of concrete throughout the world. Starting with 25 founding rebar companies and a staff of one person with a part-time helper, CRSI today claims over 135 member companies, who make or distribute rebars, and twelve Chicago-based staff members. The following highlights illustrate some of the major accomplishments that crowd the history of CRSI. In steel improvements- in 1925, only one year after its founding, the Institute succeeded in reducing the number of sizes of reinforcing bars being sold to eleven standard ones. In 1932 CRSI began developing standards for improved bar supports and spacers. Updating these standards continues today. The ASTM Specifications for Grades 60 and 75 and for Numbers 14S and 18S bars were adopted in the late 1950's. In reinforced concrete- in 1927-28 the first Standard Building Code for reinforced concrete was drafted by CRSI and adopted by the American Concrete Institute. CRSI research at Lehigh University showed that a small amount of rust on rebars improves bond to concrete. In the early 1960's design riles for Grade 60 rebars were introduced and also 24,000 psi allowable stress in the 1963 ACT Building Code under working stress design. In 1970 CRSI and the Prestressed Concrete Institute jointly undertook a promotion program on long-span prestressed reinforced concrete box girder bridges.