Welded Hollow Hlau Rooj Ncej

Ib qho welded hollow hlau qhov rooj yuav siv rau ob daim ntawv thov sab hauv thiab sab nraud. Cov hlau hluav taws xob yog muab rau txhua txoj kev mob phab ntsa, txawm tias tshiab lossis uas twb muaj lawm. Thav ntawv tau sib sau ua ke; Squared, welded, av du thiab prime pleev xim. Welded fab uas tau muab ib tug zoo li tsis muaj tseeb.