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Full text of "Metallurgy Of Cast Iron"

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TUKKMAI,   TKSTS,    K'lV. ,    l-'OK    CAR    \\1IK.KLS.             445
No. i, or highest contraction number, for the test. If tape No. i fails when in the thermal test, reject such, and allow the inspector to select one of tape No. 2, or next lower contraction mini her; and if the second wheel fails reject all of the wheels represented. Providing, however, the second wheel stands the thermal test, it seems hardly fair to tin* manufacturer to condemn the second and lower shrinkage numbers, the inspector bein^' satisfied by the test <>n the second tape sizes that tin1}' are sufficient ly strong and are hard enough to ij'ive the wear. An inspector should make a study of iron, so that lie can readily designate at a glance whether the first wheel failing could be attributed to bad iron or abnormal conditions in the pitting or handling of the rejected wheel. A wheel can be made of a hard close i,»Tain iron that will stand the drop test or concussion in service, hut if subjected to a severe and continued brake application is liable, as boys say, il to ;»o up in smoke." A gritty, hard chill will not make tin* mileage that a toiivdi chilled \vheel will. A gritty Hi ill will shell out <piieker than a tou^h one, beeatise it will not stand the heat that is caused by severe brake application, flood white iron is tottidi, as well as brim* hard enotudi. There is as threat a difference in the ijuality of white in>n as there is in t^ray Iron; had white iron has a Inr^v proportion of sulphur. 1 believe tile Steel-tired wheel proves I hat the toughness jL'j'v** the wi'ar. 1 have not seen or heard of a steel -tired wheel .shelling out, I have heard some »ad men say that when t hey ran rut t lie chill of a. wheel with a chisel, the wheel will not make i',ood mileage. If this is the ease the steel \vbed eoiihl not make the mileage that is claimed for it, 1 the steel-tiredrcf.    Ilirlinn* whrii thr pomm-»'r-r.r-,