THREADED JOINT FOR STEEL PIPE AND METHOD OF THREAD PRODUCTION

摘要

FIELD: mechanic engineering. ^ SUBSTANCE: invention relates to threaded joints. Threaded joint for steel pipe includes nipple and coupling with contacting surface provided with threaded part and non-threaded part for metal contact. In metal contact, hard lubricating film is available on contacting surface of nipple or coupling. Hard lubricating film contains one or more types of powder lubricants selected from graphite powder lubricants, mica, calcium carbonate and kaoline, copper powder and binding agent. ^ EFFECT: multiple connection and loosening of threaded joint avoiding hazardous effect on human body and environment; ensured with significant strength to seizure and corrosion, improved leak tightness. ^ 10 cl, 4 dwg, 5 tbl