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ASTM A 106 Black Carbon Seamless Steel Tubes yamitundu yosiyanasiyana yogwiritsira ntchito kutentha kwakukulu
Ku Botop, ndife olemekezeka kukhala nthambi yapadziko lonse ya Hebei allland Steel Tube Group, ndipo timakhalanso ndi machubu ambiri osasokonekera kuti tikwaniritse zosowa za makasitomala.Werengani zambiri