Durability & Kev Kho Tsawg
Tag nrho cov ntaub ntawv raw tau raug kuaj nruj rau qhov muaj pes tsawg leeg, hardness, thiab qhov tseeb qhov tseeb. Cov khoom siv tseem ceeb yog ua los ntawm cov khoom zoo siab - cov hlau zoo thiab cov alloys, thaum cov khoom siv hluav taws xob, hydraulic, thiab kis tau tus mob yog los ntawm cov npe nrov thoob ntiaj teb.
