ASME B18.2.1 UNF Fine Thread Hex Bolt Grade 5 Black Oxide

Mbiri ya ulusi wa National American (60 profile angle and H/8 flatness) ndi yosiyana ndi mbiri ya Wyeth (55 profile angle ndi H / 6 flattening kutalika). American National Thread imagwiritsidwa ntchito kwambiri m'magawo ndi mafakitale omwe amakhudzidwa ndi mafakitale aku America. Mu Nkhondo Yachiwiri Yapadziko Lonse, chifukwa cha kusagwirizana kwa ulusi wogwiritsidwa ntchito ndi Allies, zovuta zoperekera katundu zidabweretsa kuwonongeka kwakukulu kwachuma ndi kuvulala kwa Allies. Nkhondo yachiwiri yapadziko lonse itangotha, United States, United Kingdom, Canada ndi mayiko ena ogwirizana nthawi yomweyo anayamba kupanga ulusi wogwirizana pakati pa mayiko ogwirizana, ndipo adalengeza muyeso wogwirizana mu 1948.

Chifukwa mphamvu zachuma ndi mphamvu zankhondo za United States zinkalamulira magulu ankhondo a Allied panthawiyo, ulusi wogwirizana udapangidwa makamaka molingana ndi chikhalidwe cha United States. Umodzi"; chilembo chomaliza "N" chimachokera ku dzina la "N" la American National Threads. Kuyambira pamenepo, ulusi wogwirizana unayamba kufinya msika wogwiritsidwa ntchito woyambirira wa ulusi wa British Whitworth.