air-hardening

[air-hahr-dn-ing]

adjective

Metallurgy.

1. noting any metal, especially alloy steel, that can be hardened from above its transformation point by cooling in air.

air hardening

noun

1. a process of hardening high-alloy steels by heating and cooling in a current of air Compare oil hardening

Word History and Origins

Origin of air hardening¹

First recorded in 1905–10

Example Sentences

The connecting rods are of “H” section, machined all over from forgings of a special air-hardening chrome nickel steel which, after being heat treated has a tensile strength of 280,000 pounds per square inch.

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Air-hardening Steels.—These steels are recommended for boring, turning and planing where the cost of high-speed seems excessive.

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Owing to the air-hardening property of the steel, the drop-forgings should be trimmed while hot.

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The gear steel specified is of the air-hardening type.

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Page 116 Annealing Work.—With the exception of several of the higher types of alloy steels, where the percentages of special elements run quite high, which causes a slight air-hardening action, the carburizing steels are soft enough for machining when air cooled from any temperature, including the finishing temperature at the hammer.

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