Our roller shutters doors are constructed from curtains formed of 0.8mm galvanised steel and contain the double angle stiffening bottom bar riveted to bottom slat. Heavy-duty steel spring-barrel shaft with adjustable oil tempered helical balance, supported on mild steel brackets and bolted to steelwork/concrete. Guide formed from 3mm thick x 75mm deep galvanised steel channels, with options of Chain operated, Push-Up or Automated.