The Masonmate Heavy Duty Anchor AU heavy duty anchor product in the range of M6, M8, M10, M12, M16 and M20 is an anchor made of galvanised steel. AUH anchor includes has a hexagonal head; AUC anchor has a countersunk head. The anchor is installed into a predrilled cylindrical hole and anchored by torque-controlled expansion. The anchorage is characterised by friction between the expansion tube and the concrete.