Cov txheej txheem hlau ua rau" ntxhib" ua, uas txhais tau tias tsuas yog txiav yooj yim, vuam, khoov, drilling thiab lwm yam txheej txheem ua haujlwm tau siv rau qhov khoob kom ua rau cov khoom tiav. Nws ua qhov loj me, cov duab thiab lwm yam yuav tsum tau muaj tsawg. Piv nrog rau kev ua haujlwm, kev ua tiav tsis yog lub tswv yim qib. Cov txheej txheem feem ntau suav nrog H-puab cov kem hlau, nqaj hlau, kab sib chaws, kem nqaj, cov qauv hlau tsim, lwm cov tswv cuab zoo tib yam, thiab lwm yam. ua haujlwm, thiab ua kom raug ntawm cov cuab yeej siv ib txwm xws li tshuab txiav nplaim taws, tshuab dabtsi yog khoov, phaj txiav, H-nqaj sib dhos, vuam gantry, tua peening tshuab thiab txau cov khoom tsis siab. Txhawm rau ua cov txheej txheem hlau loj, yuav tsum muaj cov cuab yeej ua haujlwm tshwj xeeb, xws li cov khoom siv loj-txoj kab hluav taws xob solenoid vuam thiab cov khoom siv vuam tsis zoo. Cov tub ntxhais ntawm cov qauv hlau ua yog vuam. Qhov zoo ntawm cov khoom siv vuam ncaj qha cuam tshuam txog kev ua haujlwm ntawm lub hoobkas. Ib txoj kab H-beam tsim muaj cov neeg ua haujlwm txuas ntau tshaj plaws, thiab qib cov neeg ua haujlwm vuam yog tus yuam sij.
