Kev ua rau cov khoom ntim yuav tsum muaj cov khoom muaj txheej txheem zoo dua qub thiab muaj zog, txo qis dua thiab laus cev, feem ntau yuav tsum tau carbon steel elongation δ ≥ 16%, yield ratio σs / σb ≤ 70%, Low Alloy siab zog δ ≥ 14 %, σs / σb ≤ 80%. Txwv tsis pub, kev thim txoj hauv kev ua haujlwm tsis zoo, thiab qee qhov kev ntsuas yuav tsum raug muab coj los tso rau hauv qhov kev ua cov hlau qhov chaw ua haujlwm, qhov no ua rau cov nqi raug tsim ntawm cov khoom.
Cov pwm yog qhov khoom siv rau kev thev naus laus zis. Qhov zoo ntawm qhov dav, qhov ntev, kev tsim tau, thiab kev pabcuam ntawm kev cuam tshuam ntawm kev cuam tshuam cov khoom muaj feem xyuam nrog ua pwm qauv thiab nws cov qauv tsim. Raws li kev sib xyaw ntawm kev xyuam xim, muaj: hom hom hom yooj yim, ntau hom kev nruam thiab ntau hom.
Cov khoom siv thwj thwm muaj xws li cov khoom siv tshuab thiab cov xovxwm hydraulic. Hauv high-volume ntau lawm ntawm cov khoom sib txuas hlau, cov qib siab ceev ceev los yog ntau qhov chaw nres tsheb yuav tsum siv kom deb li deb tau; hauv cov khoom me me, tshwj xeeb tshaj yog nyob rau hauv cov zauv ntawm qhov loj qhov me me slabing khoom, hydraulic presses feem ntau siv.
Cov khoom ntim ua haujlwm, cov lej tsuas yog cov phaj, khij nyiab, yeeb nkab thiab lwm cov khoom siv, kev siv cov khoom siv thwj thawm los ntawm lub luag hauj lwm ntawm cov pwm, kom lawv tau txais qhov tsim nyog thiab qhov loj me. Cov ntaub ntawv, pwm thiab khoom siv yog peb lub ntsiab ntawm kev thim nyiaj