Raws li qhov kev sib txuas bears load, bolts tau muab faib ua ob hom: txheem bolts thiab bolts npaj rau kev siv hauv qhov remed. Raws li lub taub hau zoo, ntau yam muaj xws li hexagonal hau, puag ncig lub taub hau, square hau, countersunk taub hau, thiab lwm yam; ntawm no, lub taub hau hexagonal yog feem ntau siv. Feem ntau, countersunk taub hau yog ua hauj lwm nyob rau hauv daim ntawv thov qhov twg ib tug flush nto yuav tsum tau nyob rau ntawm qhov chaw sib txuas.
U-bolts (paub ua lus Askiv li "U-bolts") tsis yog-tus qauv fasteners. Vim lawv qhov txawv U-puab, lawv kuj raug hu ua "U-bolts." Ob qhov kawg feature threads tsim los koom nrog txiv ntseej. Lawv feem ntau yog siv los ua kom ruaj ntseg cov khoom siv tubular- xws li cov kav dej - lossis cov khoom tiaj tus, xws li cov nplooj ntoo hauv tsheb. Lub npe "U-bolt" (lus txhais tau tias "sib-nees bolt" hauv Suav) yog los ntawm qhov tseeb hais tias tus yam ntxwv uas nws ruaj ntseg ib yam khoom zoo li tus neeg caij nees. Raws li xov ntev, U-bolts tau categorized ua ob hom: tag nrho threaded thiab ib nrab threaded.
Raws li xov profile, bolts tau muab faib ua ob hom: ntxhib-pitch threads thiab fine-pitch threads; qhov ntxhib- lub suab npe feem ntau raug tshem tawm ntawm lub bolt cov cim. Bolts tau muab faib ua yim qib: 3.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, thiab 12.9. Bolts ntawm Qib 8.8 thiab siab dua (xws li 8.8) yog tsim los ntawm qis- carbon alloy steel lossis nruab nrab- carbon steel thiab tau txais kev kho cua sov (quenching thiab tempering); cov no suav nrog hu ua "siab-lub zog bolts." Bolts hauv qab Qib 8.8 (tsis suav nrog 8.8) yog sau ua ke hu ua "ib txwm bolts."
Cov bolts zoo ib yam tau muab faib ua peb qib -A, B, thiab C- raws li lawv qhov raug tsim. Qib A thiab B raug suav tias yog "ua kom zoo" (precision-machined) bolts, thaum Qib C suav hais tias yog "ntxhiab" (rough-machined) bolts. Rau kev sib txuas bolts siv nyob rau hauv cov qauv steel, tshwj tsis yog lwm yam tshwj xeeb sau tseg, tus qauv xaiv yog qhov zoo tib yam, ntxhib- qib (Qib C) bolt. Cov txheej txheem tsim khoom sib txawv ntawm cov qib no, feem ntau sib xws rau cov hauv qab no:
① Qib A thiab B bolts feature shanks uas yog precision -machined ntawm lub tshuab dhos, ua rau cov npoo du thiab meej qhov ntev. Lawv feem ntau muaj cov khoom ua tau zoo ntawm qib 8.8. Txawm li cas los xij, lawv txoj kev tsim khoom thiab kev teeb tsa, ua ke nrog lawv cov nqi siab dua, txhais tau tias lawv tsis tshua siv.
② Qib C bolts yog tsim los ntawm unmachined round steel tuav; yog li ntawd, lawv qhov ntev tsis muaj qhov siab precision. Lawv feem ntau muaj cov khoom ua tau zoo ntawm 4.6 lossis 4.8. Thaum lawv nthuav tawm ntau dua deformation thaum siv hauv kev sib txuas shear, lawv muab kev yooj yim ntawm kev teeb tsa thiab cov nqi tsim khoom qis, ua rau lawv siv dav hauv kev sib txuas nro lossis rau kev sib txuas ib ntus thaum sib dhos.