Tshwj rau txoj kev tsim kev lag luam ntawm lub pluaj. Bolt tsim thawj yuav tsum tau yuav cov khoom siv ntawm txoj kab nruab nrab ntawm tus qauv steel, thiab mam li nqes tau ib lub xaim ntawm ib lub taub. Yog tsis muaj teeb meem nyob rau hauv Suav teb no. Nyeg Baosteel thiab lwm lub lag luam muaj peev xwm muab tau cov ntaub ntawv zoo raw li, thiab pwm cov duab thiab cov txheej txheem kuj tseem khov heev.
Cov kauj ruam tom ntej yog qhov txheej txheem txias ntawm lub bolts. Txoj kev no yuav tsum siv lub cav txias. Feem ntau, lub plawg raug yuav tsum tau muaj 5-chaw nres tsheb txias tshuab. Qhov chaw nres tsheb thawj zaug yog cuam tshuam, thiab cov hlau yog tu raws li ib lub sijhawm ntev, thiab qhov ntev ntawm qhov seem tawg yuav xav tau precisely tswj. Tom ntej ob peb noj yog cov tsim ua cov bolts (tshwj tsis yog cov xov). Cov txheej txheem no yuav tsum muaj kev tswj ntawm qhov ntev, inch, thiab lwm qhov tseem ceeb, thiab tolerances yuav tsum tau tswj ntawm qhov 0.01mm. Ntxiv nrog rau qhov ruaj khov ntawm lub tshuab txias, qhov txheej txheem no yuav tsum muaj qhov siab tshaj plaws rau cov cua txias lub npe pwm. Tom qab tag nrho, tag nrho cov dimensions yog guaranteed los ntawm pwm. Qhov teeb meem ntawm kev vaj tsev yog hais tias cov moulds tau ua nyob rau hauv Suav teb, tab sis lub tshuab txias siab heev yog monopolized, American National Machine thiab cov German thiab Japanese manufacturers. Lub domestic thiab Taiwanese Leng Dun aircraft yeej monopolize cov lag luam tsawg-kawg.