Dab tsi yog cov ntaub ntawv xov
Standard self-tapping ntsia hlau cim cim, nrog rau cov cim uas sawv cev xov zoo thiab tus Tsov tus tw. Self-tapping screws muaj ib los yog ob lub cim xov los qhia cov xov hlau lossis cov xov dav (SPACED). Piv txwv li, tus cim cim "B" sawv cev rau cov xov dav dav. Cov uas tsis muaj "B" sawv cev rau cov xov hlau, thiab qhov kawg sawv cev rau cov cim kom paub qhov txawv ntawm tus kheej tapping ntsia hlau yog nws tus kheej tapping ntsia hlau, xov ntsia hlau, txiav ntsia hlau, dov ntsia hlau los yog tus kheej tapping ntsia hlau.
Cov xov hlau muaj tib yam 60-degree xov lub kaum sab xis thiab tib lub tuab thiab nyias xov suab zoo li Anglo-American unified thread. Yog tias cov ntsia hlau ploj lossis xav tau tom qab disassembly, nws tuaj yeem hloov nrog tus qauv ntsia hlau fastener.
Wide threads muaj lub kaum sab xis ntawm 60 degrees tab sis lub suab dav dua. Vim nws lub suab dav dua, nws muaj cov xov steeper dua li cov xov hlau, thiab nws kuj muaj cov ntsia hlau loj dua. Kuj tseem muaj cov xov tshwj xeeb uas siv rau ntawm cov yas, nws lub kaum sab xis yog 48 degrees, feem ntau hu ua PT ntsia hlau.
Self-tapping screws A, AB, B, BP, C thiab lwm hom tau maj mam hloov los ntawm dov nws tus kheej tapping screws, yog li lawv tsis pom zoo siv rau hauv cov qauv tshiab. Qhov sib txawv ntawm AB, B thiab BP nkaus xwb yog cov duab ntawm tus Tsov tus tw. AB muaj ib tug threaded cone, B muaj ib tug blunt tail, thiab BP muaj ib tug tsis threaded cone. Qhov nruab nrab ntawm tus taw tes taw mus rau hauv lub qhov pre-drilled thiab pib tsim cov xov. Xov txiav self-tapping screws muaj BF, BP, D, F, G, T thiab lwm yam ntaub ntawv. BF thiab BP yog cov xov dav, thiab cov seem yog cov xov hlau.
Qhov txawv feature yog lub cuttail. Txhua hom kev txiav plaub hau muaj cov duab uas khaws cov khib nyiab los ntawm kev txiav. Yog hais tias tus kheej-tapping ntsia hlau yog ntsia rau hauv qhov muag tsis pom (lub qhov uas tsis tau dhau los), nws cov khoom tawg yuav nyob hauv qab ntawm lub qhov thiab kaw. Txawm li cas los xij, yog tias lub qhov yog tapping, cov khoom seem ntawm sab nraud ntawm lub workpiece. Yog li ntawd, xws li tus kheej tapping screws yuav tsum tau txiav txim siab thaum xaiv xws li tus kheej tapping screws. Cov khib nyiab tuaj yeem paug, poob rau hauv qhov chaw ua haujlwm, lossis ua rau cov khoom siv hluav taws xob tsis tuaj yeem ua haujlwm.
Tag nrho cov dov self-tapping screws yog tshuab xov, tib yam li Anglo-American Unified Thread ntxhib suab xov. Thov xa mus rau SAE J81 cov cai. Rau metric threads, thov xa mus rau SAE J1237 thiab DIN7500.
nruj
Muaj ob hom ntawm tus kheej-drilling thiab self-tapping screws: txiav dav xov BSD thiab txhua yam xov CSD. Kuj tseem muaj cov xov tshwj xeeb, suav nrog cov xov siab thiab qis dua, thiab ntau yam tapping thiab drilling tails kuj tsim nyog. Vim qhov xwm txheej ntawm tapping thiab threading, qhov kawg laum screws tsis haum rau kev ua haujlwm qhov muag tsis pom. Thaum sib dhos tus kheej-drilling screws, laum tus Tsov tus tw yuav tsum tau nkag mus rau hauv lub workpiece kom txiav los yog ua cov xov. Yog li ntawd, feem ntau muaj qee qhov tawg. Chiping yog unavoidable yog hais tias thread txiav yog siv. Yog li ntawd, yuav tsum tau txiav txim siab ua. qhov teeb meem no. Thov xa mus rau SAE J78 thiab DIN7504 (wide thread) rau BSD thiab CSD tus kheej-drilling screws.
