au·​to·​fret·​tage | \ ˈȯ-tō-ˌfre-tij\
plural -s

Definition of autofrettage

: the application of such interior pressure to the bore of a heavy ordnance gun as will deform the inner layers of steel beyond the elastic limit that would be reached by the explosion of any charge to be used subsequently in the gun

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First Known Use of autofrettage

1919, in the meaning defined above

History and Etymology for autofrettage

probably from French, from aut- + frettage

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The first known use of autofrettage was in 1919

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