Bolted glazing

Bolted Glazing

Exterior bolted glazing systems are a modern solution to many challenging architectural design briefs that demand light and spaciousness.

The use of sophisticated bolted glazing systems, where glass panels are attached directly to structural steelwork without using any intermediate framing, has grown significantly in recent years.

These Frameless bolted glass structural systems offer architects and specifiers opportunities for creating original designs in glass, in any plane from vertical through to horizontal in single glazed, double glazed and laminated versions.

The glass is held in place using a bolted assembly structure as opposed to the traditional curtain walling systems that are fixed into frame panels. This provides a frameless ‘all-glass’ appearance which not only provides maximum visibility but also allows full use of natural daylight and the ability to showcase the interior features of a building.

Bolt fixings attach the glass panels to brackets on the steel through pre-drilled holes in the panels. The bolts provide point support instead of the continuous edge support given by conventional frames.


  • Freedom of design
  • Unobtrusive, flush appearance
  • Can be installed on any plane
  • Maximises daylight penetration
  • Tamper Resistant Bolt fixings
Product Advantages

Bolted glass systems are ideal for a variety of facades and roofing structures, particularly atriums and viewing decks where light and visibility are paramount.

Frameless bolted glass structures enable a completely flush exterior, unlike any other form of glazing. Unique mechanical fixings create clean and uninterrupted glass structures without any external framing

The high grade stainless steel fixings are designed to absorb all static and dynamic loads, including the dead weight of the glass, wind loading, snow loads and differential expansion due to temperature difference, and distribute them to the support structure.

The intermediate elements which are inserted between the bolt and the glass ensure a watertight façade and uniform transmission of stresses whilst avoiding local stresses.

Product Construction

Using specially designed Pilkington Planar™ fittings, single toughened, insulated or laminated glass panels are fastened back to the support structure. These highly engineered and tested bolts are countersunk into the glass to allow a flush exterior surface.

Loads incident on the glass are transferred through the Pilkington Planar™ fittings and spring plates into the structure.

Various forms of steel structures can be used to support a Pilkington Planar™ façade. The design of these structures can be varied and either simple – in the form of mullions, or intricate, in the form of trusses.

The versatility of Pilkington Planar™ connections enables almost any type of structure to be used.

An Architect can select from an extensive library of cast spring-plates whether the connection detail be at the cruciform (4 point connection) or at the intermediate location (2 point connection). All of these castings provide adequate movement capability and have been designed to support the reactions which would be expected at the fitting locations of a typical facade.

Planar™ Bolts are available in two types: 902 and 905.

The 902 bolt fitting fixes directly to the secondary structure by means of Pilkington Planar™ spring plate brackets or castings. The 902 can accommodate any angle of slope – making it ideal for roofs and canopies.

The 905 Fitting is the most popular Pilkington Planar™ fitting which eliminates the need for spring plates and allows absorption of live loads and thermal expansion by rotation round a steel pin connected to the back-up structure. The fitting can also be articulated to allow use in facetted façades.

Articulated fixings are often used in conjunction with large panes on tall or long span, steel structures. As the glass panels and the supporting structure bend under the combined effects of self-weight and applied loads, articulated bolts allow some rotation of the fixing.


Pilkington Planar™ fittings are made from 316-type stainless steel, delivering impressive aesthetics and avoiding unsightly or even unsafe deterioration due to environmental conditions.

Spring plates can be made from stainless steel, mild steel or aluminium alloy. Both elements are available in a variety of finishes to suit the application.

The fittings in the Pilkington Planar™ system offer the ideal balance between durability and appearance. Highly engineered and tested components offer the smallest and most aesthetically pleasing fittings available without compromising on performance.

When required, the mechanical strength and the corrosion resistance of the fittings can also be enhanced by the use of Duplex and Precipitation Hardened alloys.

To learn more about this product and for detailed information browse through the datasheets below.