Coj los ntawm kev tshawb fawb txuj ci thiab thev naus laus zis ib txwm ua rau sab nrauv thiab cov txheej txheem rau kev txhim kho ntawm cov thev naus laus zis. Aluminium vaj huam sib luag qab nthab peb cog lus tias peb muab txhua tus qhua nrog cov khoom lag luam zoo suav nrog cov vaj huam sib luag zoo suav nrog cov vaj huam sib luag qab nthab thiab kev pabcuam zoo. Yog tias koj xav paub cov ntsiab lus ntxiv, peb zoo siab tau qhia koj.Qhov khoom muaj qhov kom zoo dua ntawm cov hardness txaus. Nws muaj cov cuab yeej los tiv thaiv nias-hauv lossis kos ntawm cov khoom ntse.


