Txoj kev teeb ncej ntawm peb lub tuam txhab yog tsim los ntawm cov ntawv zoo.Peb muaj cov kab ntau lawm, nws suav nrog lub tshuab flatting, steel phaj shearer, dabtsi yog khoov tshuab, pib kaw tshuab, submerged arc vuam tshuab thiab marine txheej kab.