Cov teeb tsa screws tau siv los kho qhov txheeb ze ntawm qhov mechanism. Ntsia cov ntsia hlau teeb rau hauv lub qhov ntswj ntawm lub qhov kom ua kom nruj, thiab nias qhov kawg mus rau qhov chaw ntawm lwm qhov, uas yog, kho yav dhau los mus rau ntu tom ntej.
Cov teeb tsa ntsia hlau feem ntau yog ua los ntawm cov hlau tsis muaj steel lossis stainless, thiab nws cov qauv ntsis yog tapered, concave, tiaj, cylindrical thiab tshaj. Qhov kawg ntawm qhov kawg tapered lossis qhov kawg concave ntawm lub teeb ntsia hlau ncaj qha ntu ntu, uas feem ntau siv rau cov khoom siv tom qab kev teeb tsa; qhov kawg ntawm cov tiaj tiaj kawg teeb tsa ntsia hlau tau yooj yim, thiab qhov saum npoo ntawm qhov tsis muaj qhov puas ntsoog tom qab ua kom nruj, thiab siv rau feem ntau kho qhov chaw. Ntawm qhov sib koom ua ke, tsuas muaj lub nra me me tuaj yeem sib kis tau; qhov cylindrical kawg zawm ntsia hlau siv los kho qhov chaw ruaj khov kho ntau zaus, nws tuaj yeem tiv taus qhov hnyav, tab sis qhov kev ua haujlwm tiv thaiv tsis ua haujlwm tsis zoo, thiab cov txheej txheem tiv thaiv xoob yuav tsum tau ua thaum kho; Lub hau ntsia hlau yog qhov tsim nyog rau kev kho qhov chaw nrog cov phab ntsa tuab.