NOTE: The grade designation used herein comprise the letter X followed by the first two digits of the specified minimum yield strength. 1. This specification covers high-test line pipe in grades X42 and higher. Requirements on grades X42@ X46@ and X52 are fully specified@ Requirements on intermediate grades (those between X42 and X46 and between X46 and X52) and on grades higher than X52 are specified except for chemical compositions and certain physical properties which are subject to agreement between the purchaser and manufacturer@ within the limitation that the agreed-upon requirements must be consistent with and proportional to the corresponding requirements specified herein for grades X42@ X46@ and X52. 2. Nothing contained in this specification is to be construed as granting any right@ by implication or otherwise@ for manufacture@ sale@ or use in connection with any method@ apparatus@ or product covered by letters patent@ nor as insuring anyone against liability for infringement of letters patent. This specification is for the convenience of purchasers and manufacturers in ordering and producing pipe and is not intended to inhibit purchasers and producers from purchasing and producing pipe meeting specifications other than those contained herein nor is it intended in any way to inhibit purchasers from purchasing pipe from companies not authorized to use the API monogram.