System 5-20


Aluminium tilt and turn window, which can be tilted open for ventilation, or fully opened for internal cleaning and maintenance; available in dual colours and a range of glazing options.


Profiles are extruded from aluminium alloy (6060 T6, T5 or T4 to BS EN 12020-2/ BS 755-9). Outer frame sections are minimum 50 mm deep and incorporate two 20 mm polyamide thermal break sections. Structural profiles are designed so that the maximum deflection of any member will not exceed 1/175 of its span, with no evidence of permanent deformation once the load has been removed.

Joints in outer frame and vent members are formed with 45° mitres, reinforced with extruded aluminium cleats and stainless steel corner braces. Corner joints are glued and pneumatically crimped. Mullions and transoms are secured using stainless steel screws driven into snap-in fixing cleats which locate into the bead grooves within the framing sections. Joints are sealed using a small gap sealant.

Windows incorporate a pressure equalized drainage system. Opening vents have an internal flipper gasket with moulded corners fitted to their perimeter; fixed lights have concealed drainage with external, ‘snap-on’ drainage covers.


With suitable glazing, windows can contribute to meeting the requirements of Building Regulations for conservation of heat and power. Consult Metal Technology for further recommendations and details.

The windows provide Class IV weathertightness as defined by BS 6375-1 and BS 5368:

  • Air permeability: 600 Pa.
  • Watertightness: 600 Pa.
  • Wind resistance: 2400 Pa.


Lugs and/ or frame anchors used to secure windows to the building structure must accommodate predicted loads and deflection within design tolerances. Generally, fixings must be positioned 150 mm from each corner and each mullion/ transom, and at centres not exceeding 600 mm. Fixing lugs/ straps should be used only where they can be suitably concealed.

Secured by Design:

  • All glazed curtain walling screens, windows, and doors within the ground floor and vulnerable areas are secure by design.
  • areas are secure by design.All systems installed are tested in line with PAS 24 security standards and certified by a UKAS accredited certification body.

General information


As drawing ___

As schedule ___

Uniclass 2015

Pr_30_59_98_02 Aluminium window unitsPrimary


L10/25 Aluminium windows

L10/330 Aluminium windows

Specification data - Aluminium window units

Product Reference

System 5-20 Polyamide Casement


As drawing ___

As schedule ___

Glazing details

24 mm insulating glass units

26 mm insulating glass units

28 mm insulating glass units

30 mm insulating glass units

32 mm insulating glass units

Glazing method

Factory fitted

Site glazed

Ironmongery/ Accessories

Manufacturer’s standard

Product Options


Limiting dimensions for opening vents:

  • Height: 2100 mm.
  • Width: 1500 mm.
  • Weight: 100 kg.

Maximum length and width cannot be obtained simultaneously; refer to gearing manufacturer’s guide for configuration options.

Finish as delivered:

Aluminium sections are polyester powder coated to BS 6496, with the option of different interior and exterior colours. Consult Metal Technology for availability of colours and to obtain samples.


Windows can accommodate a range of insulating glass units and can be glazed in the factory or on site. Windows are dry glazed using ‘snap-in’ extruded aluminium beads with colour coded, co-extruded, PVC nitrile, captive ‘E’ gaskets externally and ‘wedge’ gaskets internally. Consult Metal Technology for recommendation and details.

Ironmongery/ Accessories:

Tilt and turn gearing is located within integral Euro Grooves extruded within the sections, and concealed in the hinge cavity. Gearing is sized according to vent size and weight.

Standard locking handles restrict the operation of the window to ventilation mode, unless they are unlocked for cleaning; re-locking the handles returns the window to ventilation mode.

Consult Metal Technology for recommendations and details of additional ironmongery options.

Similar products from Metal Technology Ltd

System 1-35Hi Window

System 1-35Hi+ Window

System 1-35Hi+ Window

System 15 Secondary Glazing

System 15 Secondary Glazing

System 20 Horizontal Sliding Window

System 20 Horizontal Sliding Window

System 4-20 window

System 4-20 window

System 4-20Hi+ Thermally Enhanced Polyamide Casement Window

System 4-20Hi+ Thermally Enhanced Polyamide Casement Window

System 4-35Hi Windows

System 4-35Hi+ Windows

System 4-35Hi+ Windows

System 5-20 Polyamide Tilt and Turn Window Panel Adaptor

System 5-20Hi+ Window

System 5-20Hi+ Window