Case hardening

Definition and stakes

Archibald Sharp,  1911 Encyclopædia Britannica (1910)

“ The ball-races are often made of separate pieces of steel, but the crank-axle usually has the cones formed integral with it, the necessary hardness being obtained by case-hardening. According as the two cups face outwards or inwards the bearing is said to have outward or inward cups, and according as the adjustable ball race is the cone or cup, the bearing is said to be cone-adjusting or cup-adjusting. Fig. 3 shows a ball-bearing hub with outward cups. The hub-shell H is turned out of mild steel, and the cups C are forced into the ends of the hub-shell and soldered thereto. ”
Source: Wikisource

Archibald Sharp,  1911 Encyclopædia Britannica (1910)

“ Steel of 75 to 100 tons per sq. in. tensile strength is used in chains, spokes, &c. In balls and ball-races, hardness without brittleness, and homogeneity are of primary importance. Broken balls, or even traces of wear in bearings, are now seldom heard of in a first-class bicycle. The process of case-hardening, whereby an extremely hard outer skin is combined with a tough interior, has been brought to a high degree of perfection, and is applied to many parts of the bicycle, particularly chains, free-wheels and toothed-wheel variable speed gears. ”
Source: Wikisource

Robert O. Harland,  The Vice Bondage of a Great City…

“ The police when compelled by the pressure of public opinion are obliged to resort to the bolstering of a case.
Judging from later developments innocent men have been arrested on serious charges, thrown into filthy and unsanitary cells, dragged to the Criminal court and subjected to the most shameful and humiliating treatment, in order that the police force may purge itself temporarily from the stigma of being inefficient.
It is only a matter of inference, but it seems probable that hundreds of confessions of crimes are wrung from innocent victims by the brutal “third degree” methods.
”
Source: Gutenberg

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