Gi square hollow ntu square raj ntau lawm
Qhov tseeb ntau lawm rau gi round steel yeeb nkab thiab gi square hollow seem yuav luag zoo ib yam.
Qhov txawv tsuas yog muaj ib kauj ruam ntxiv rau cov square hollow seem uas peb yuav hloov dua tshiab tom qab ua tiav cov kav dej hloov. Ua kom cov yeeb nkab hloov mus rau hauv cov yeeb nkab square.
Yog li rau qee qhov txuas ntxiv, cov yeeb nkab square yuav me ntsis kim dua li ntawm cov puag ncig yeeb nkab.
Yog tias koj muaj dab tsi xav paub ntxiv, txais tos hu rau peb txhua lub sijhawm. Peb yuav muab cov lus piav qhia tshaj lij kev tshaj lij. Txais tos !!!
