This series has its origins in the “Universal Range”, which was introduced for the first time in 1912 by the British company “The Crittall Manufacturing Co. Ltd.”. The Universal range consisted of three different ranges of hot rolled profiles, identical in geometry and types, but different in their depth, that classified them into large, medium and small. Depending on the dimensions of the window, the most appropriate series was selected to match the static requirements. These three ranges were able to cover any type of window and opening. In combination with special T-profiles, used as mullions and transoms, for the first time it was also possible to realize curtain walls of any size. The currently available range was revised in 1964 and re-coded as “W20”. The three separate ranges were condensed into one medium range, which consisted of 20 hot rolled profiles able to cover the functions of modern windows and grant the original design and proportions for those to be replaced in historic buildings. Even today, after more than 100 years, this timeless series is still chosen for a great number of restoration projects worldwide.


1. Solid hot rolled steel profiles
2. Classic “Stepped leg” design
3. Material thickness up to 5 mm
4. Self-adhesive non-shrinking gaskets
5. Accommodates low emissivity doubleglazing
up to 21 mm
6. Choice of different glazing beads
7. Fixed glazing, single-sash and double-sash, side-hung and bottomhung windows opening inwards and outwards, top-hung, vertical and horizontal pivoting windows, windows and doors opening inwards and outwards