dropped apart in my hands
Fig. 3 (cropped from border and page)
illustrating discussion (anecdote, really)
to J. S. Macgregor and Bradley Stoughton. “A new method of testing the endurance of case-hardened gears and pinions.” ASTM Proceedings 11 (1911) : 822-825 (followed by discussion pp 826-832)
Princeton copy, digitized May 4, 2010
“The cracks started at the root of the tooth and came down on the border line of the good and bad metal as shown in the photograph, Fig. 3. On one side the metal was full of blowholes, too small to be seen by the naked eye; while on the other side the material was perfectly sound... After I had worked it up to where the crack as I supposed actually existed, the metal dropped apart in my hands, and showed the markings of a most beautiful heat crack, evidently the result of bad heat treatment.”
comment by Mr. G. L. Fowler, pp 827-828
rimes with metals 2 at 0017.
tags:
ASTM; beauty; metallurgy; metals
J. S. Macgregor; B. Stoughton, “A new method of testing the endurance of case-hardened gears and pinions” (1911)