Lub tuam txhab tau nruab nrog cov twj kuaj ntsuas ntshav: Vernier calipers, thickness gittance, muaj zog tensile, siab zog, elongation, thiab durabilation, thiab ruaj khov). Peb nruj ua raws li cov txheej txheem tshuaj xyuas: Cov khoom siv raw, thiab tshuaj xyuas cov khoom lag luam hauv online, ua tiav cov khoom lag luam tiav, ua tiav cov khoom lag luam tiav tsim nyog ntawm ntau dua 99%.