4.0 to 9mm, Helical(screw),Plain,indented... ASTM,BS,JIS,GB High and stable quality,competitive ... , 9.00mm, 10.00mm,3)Type of Surface: Helix(screw), Plain, indented .4)Standard: GB/T 5223-2002, ASTM A416, BS5896 ... post-tensioning technology in large, medium and small sizes of various shapes of PC structures, such as civil engineering construction of ...