Made of 1.5 or 2.0 mm Hot dip galvanized sheet steel. The joist hangers are equipped with 5 mm holes for nails/screws and 9 mm or 11 mm holes for bolts. There is also a 7 mm hole on the beam hanger flange that comes under the beam. The joist hangers are available in two designs partly with external flanges, Standard, partly with internal flanges, Type I.