J. C. Shiuh, Impact Strength of Amosite Fibers in Asbestos-Cement Products, J-M Research Report 411-708 (1968)

The one-page summary of Johns-Manville Research and Engineering Center report 411-708 of March 7, 1968, "Impact Strength of Amosite Fibers in Asbestos-Cement Products," by J. C. Shiuh of the Asbestos Evaluation and Development Section, stamped "JM CONFIDENTIAL. Not for general distribution or republication." An earlier report had found amosite usable as a substitute for "Blue fiber" (crocidolite) only in noncritical pipe. This study tested blends of 10 per cent Cape Blue, SK amosite or M amosite with 90 per cent Jeffrey 4T chrysotile and found that "the substitution of amosite for Blue fiber in pipe blends tends to increase the product brittleness."

What it shows

J-M's asbestos-cement pipe was made with blends of Canadian chrysotile and a smaller share of amphibole fiber. In 1968 the company's researchers were testing whether amosite could replace crocidolite in those blends; this report weighs the question only on product strength.