HBW Security Hinge Bolt - Bush
  HBW Security Hinge Bolts may be installed to aluminium doors and other hollow stile doors having a thickness greater than 38mm.   The HBW-Bush is manufactured from brass and includes an M12 thread to accommodate the M12 thread of HBW Security Hinge Bolts.   To enable installation without removal of a door, each bush has an M6 cross thread formed in it to facilitate insertion and positioning of the HBW-Bush within a door stile.