API TR 21D PDF
This report quantifies the hardness profile of both machined and rolled threads in precipitation hardened nickel-based alloys (PHNAs); studies the effects of both machined and rolled threads on hydrogen induced stress cracking (HISC) susceptibility in relevant PHNAs; tests these PHNA grades used for bolting per the requirements of API standards; and provides guidance for the use of the selected testing methodology and resultant test data in the petroleum and natural gas industry.
