Cov txheej txheem polishing
Qhov saum npoo yog huv thiab huv, qhov kev thauj khoom yog qhov loj, thiab kev sib txhuam me me.
Cov kabmob hlau cov khoom siv
Cov cuab yeej siv cov kabmob steel muaj kev ua haujlwm zoo thiab tsis yog yooj yim xeb.
Cov khoom siv zoo dua
Cov khoom siv zoo tshaj, dhau los ntawm ntau cov tshuaj ntsuam thiab kuaj, kom ntseeg tau cov khoom zoo.