Miyezo ya Metric, US ndi Inchi
NPT, PT, ndi G ndi ulusi wa mapaipi.
NPT imayimira National (American) Pipe Thread. Ndi American standard 60-degree taper Pipe Thread yomwe imagwiritsidwa ntchito ku North America. Muyezo wadziko lonse ukhoza kutumizidwa ku GB/T12716-1991
PT ndichidule cha Pipe Thread. PT ndi 55 digiri yosindikizidwa yosindikizidwa ya Pipe Thread, banja la wyeth la ulusi, lomwe limagwiritsidwa ntchito ku Ulaya ndi mayiko a Commonwealth. Amagwiritsidwa ntchito m'makampani amadzi ndi gasi, taper ndi 1:16, muyezo wadziko lonse ukhoza kutumizidwa ku GB/T7306-2000.
G ndi madigiri 55 a ulusi wosamata wa chitoliro, ndi wa banja la wyeth, lolembedwa G m'malo mwa ulusi wa cylindrical, muyezo wa dziko ukhoza kutumizidwa ku GB/T7307-2001.
Kuonjezera apo, zizindikiro za 1/4, 1/2, ndi 1/8 mu ulusi ndi kukula kwa ulusi, mainchesi.
Anthu mumakampani nthawi zambiri amagwiritsa ntchito mphindi kuti atchule kukula kwa ulusi, inchi ndi yofanana ndi mphindi 8, 1/4 inchi ndi mphindi 2, ndi zina zotero.
G si dzina lamba la ulusi wa chitoliro (Guan), likuchokera muyeso wa ISO, womwe umapereka ulusi wa chitoliro cha cylindrical. Kugawanika kwa madigiri 55 ndi 60 ndi ntchito, yomwe imadziwika kuti bwalo la chitoliro. Ndiko kuti, ulusi umapangidwa kuchokera pamwamba pa cylindrical.
ZG yomwe imadziwikanso kuti chubu chubu, ndi njira yakale yolembera ya NATIONAL, ndiye kuti, ulusi umakonzedwa ndi pamwamba. Malinga ndi muyezo wa ISO, R imayimira ulusi wakunja wakunja, Rc imayimira ulusi wamkati wamkati, ndipo Rp imayimira ulusi wamkati mwa cylindrical.
Kusiyana kwakukulu pakati pa ulusi wa metric ndi ulusi waku Britain ndi kuchuluka kwa ulusi pa inchi.
Ulusi wa Metric ndi 60 degrees equilateral, Inchi ulusi ndi 55 madigiri isosceles, ndi American ulusi ndi 60 madigiri.
Metric ulusi mu mayunitsi a metric, ulusi waku Britain mu mayunitsi inchi.
Ulusi wa chitoliro umagwiritsidwa ntchito makamaka kulumikiza chitoliro. Ulusi wamkati ndi wakunja umagwirizana kwambiri, kuphatikizapo chitoliro chowongoka ndi chitoliro cha taper. The awiri mwadzina amatanthauza m'mimba mwake wa payipi wolumikizidwa, mwachionekere wononga wononga ndi lalikulu kuposa awiri mwadzina.
1/4, 1/2, ndi 1/8 ndi mainchesi a ulusi wa inchi.