Steel roller shutters series 75

Steel roller shutters series 75

These are extensively used in heavy industrial and commercial applications such as Factories, Warehouses, Workshops, Loading Docks, Carpark entries etc.

Design Features

Steel roller shutters features consist of the following design features:

  1. Heavy duty curtain construction consisting of individual, roll formed, interlocking slats.
  2. High wind resistance
  3. Individual slats can be replaced should damage occur, thus reducing repair costs.
  4. Nylon end clips are used to stop lateral movement of the curtain and to provide smooth operation.
  5. Custom built to suit individual large doorway openings.
  6. Chain operated or motorised as required for specific purposes intended.
  7. Wicket gates and escape doors can be incorporated (restricted).
  8. Centre mullions allow unrestricted opening widths

Version 2

Curtain Interlocking Slats

Interlocking slats are manufactured from galvanised steel sections in the following size:-

  • Series 75 - in .8mm and 1.0mm thick.


Suggested Specifications

The roller shutter Series 75  (as specified) will be manufactured by 3rd Generation Doors. The curtain will be manufactured from roll formed, galvanised steel, having a thickness of .6mm, .8mm or 1.0mm (as specified). Each alternative slat will be fitted with a specially moulded nylon end clip to prevent lateral movement. Shutters will be supplied with roller drum, brackets, guide channels and all necessary components and installed to manufacturer's recommended specifications.

Curtain Construction

The Door curtain will be constructed using 75mm profile, galvanised, roll-formed, interlocking steel slats in thickness of .6mm, .8mm or 1.0mm as specified.

Series 75

  • Use: In small to medium size openings in commercial applications.
  • Size: Up to 3000mm high by 4200mm wide
  • Thickness: .8mm and 1.0mm

Note: Recommended maximum std. single span shutter width of 9 meters.

Nylon End Clips

Door Curtain slats are fitted with nylon end clips to stop lateral movement of the Curtain and ensure smooth operation.

Windlocks (Where Specified)

Windlock clips will be fabricated from mild steel, formed to suit specially designed guide channels and riveted to every 2nd or 4th slat as required and/or selected.

Bottom Rail             

The bottom rail will be manufactured from specially extruded, heavy-duty aluminium interlocking (to slats) angle section (small to medium sized doors).

Roller Drum

The roller drum will consist of a seamless, cylindrical tube encasing helical torsion springs matched to suit door size and weight and manufactured from a super grade wire revolving around a steel axle. The roller drum will be designed to give minimum deflection over the door span.


Windlocks will be fitted where specified or required.


Wicket gates 1200mm high by 600mm wide or escape doors 2040mm high by 920mmwide may be incorporated into doors over 2700mm high and not exposed to high wind loads.


Ventilation can be provided when specified.

Guide Channels

Guide channels will be manufactured from roll formed, galvanised steel channel section, formed to suit curtain depth and working clearance. The guide channels will be securely fixed to walls at intervals not greater than 750mm by masonry anchors and/or by welding to steelwork constructions.

Drum Wall Support Brackets

The roller shutter drum wall support brackets will be manufactured from mild steel plate, having a minimum thickness of 6mm and a maximum of 10mm thick and/or welded to suit door size and weight.

Centre Mullion

Centre mullions can be provided for multiple installations where specified, and are normally of a sliding type.


Operation is by hand chain or electrically motorised according to size and preference or as selected.


The shutter curtain and guides are supplied with a galvanised finish. All other components are given a primer coat of zinc rich grey primer.

Motorisation (When Specified)

Motorisation will be by means of an electric motor with one only three phase, geared 0.38 kw, 0.75 kw or 1.12 kw motor with self-contained floor and head limit switches, emergency hand chain drive in case of interrupted or failure of power supply. A reversing contactor up-down-stop push button station and thermal overload is supplied.

Note: All electrical wires and wiring and setting of limit switches by others (qualified electrician) is not included.

Chain Operation

Gearing will be fitted to one end of the roller shutter and matched to suit door size and weight. Gearing is to provide ease of operation and basically manufactured from Grey cast iron spur gears or mild steel machine steel gears as required (for large door applications).

Gates (When Specified)

Recommended on small to medium sized roller doors only, over 2700mm high and not exposed to high wind loading.

  • Wicket Gates normally open inside and are of 1200mm high by 600mm wide fitted 300mm above floor level.
  • Escape Doors (fire escape doors) are opened outward and are 2040mm high by 920mm wide.


Ventilation (When Specified)

Ventilation to the roller shutter curtain can be provided by punching out the interlocking slats at certain intervals for the required ventilation. Where ventilation and vermin proofing is required, the roller shutter curtain can be punched out and a galvanised steel (optional), diamond pre-formatted armour mesh can be pop-riveted to the back face of the slats.

  • Series 75 Slat - 104mm wide by 18mm high at 100 to 150mm intervals.


Centre Mullions (When Specified)

Centre door mullions will be manufactured from mild steel plate having a minimum width of 200mm to 250mm. The mullions will be supplied either being of a sliding type or a fixed type (as selected). The sliding mullion is manually operated by disengaging top and bottom levels and sliding to one side of the doorway opening on an overhead sliding door track, fixed to the underside of the door head lintel. The fixed type mullion is not removable and is fixed to the floor and door head lintel.