Raupwm puag, feem ntau, yog tias cov duab ntawm forging yog qhov yooj yim, qhov qis qis ntawm qhov tuag feem ntau yog siv los ua cov kab noj hniav tseem ceeb rau tus qauv, thiab cov tuag sab saud feem ntau yuav yooj yim dua lossis txawm tias siv lub tiaj tiaj tiaj. Yog hais tias cov duab ntawm forging yog complex thiab parting nto yog teem nyob rau hauv nruab nrab, cov kab noj hniav yuav tsum tau tsim rau ob lub Upper tuag thiab qis tuag. Feem ntau hais lus, sab sauv thiab qis tuag(pwm puag)yog siv los molding. Cov tuag qis feem ntau ua lub luag haujlwm tseem ceeb thiab cov tuag saum toj yog pab. Txawm li cas los xij, muaj cov xwm txheej tshwj xeeb. Yog hais tias lub hauv qab tuag molding tsis zoo tagnrho, lub Upper tuag yuav siv tau raws li lub ntsiab kab noj hniav, vim hais tias rov qab extrusion txoj kev yuav yooj yim dua. Qhov tseem ceeb tshaj plaws yog kom pom cov duab ntawm forging.
