Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hydril CofiledCriticalHydril Co
Priority claimed from EP84901681Aexternal-prioritypatent/EP0151574B1/en
Application grantedgrantedCritical
Publication of ATE37583T1publicationCriticalpatent/ATE37583T1/en