Glass Adaptors: Versatility and Applications

Glass adaptors are essential elements in glass construction, consisting of several components – the head, rubber gasket, spacer, and screw. Together, these elements ensure a secure and stable glass connection to the structure. They are particularly used in glass railings, French balconies, roofs, and other structures where both aesthetics and safety are required.

Glass railings mounted with glass adaptors

What sizes and applications are available?

Glass adaptors are available in various sizes, ranging from 12 mm to 70 mm in diameter. Smaller adaptors, such as those with a diameter of 12–19 mm, are suitable for securing plates and lightweight structures, while larger ones, such as 30–70 mm in diameter, are used for mounting larger glass structures.

In addition to diameter, the thickness of the spacer in glass adaptors can vary from 4 mm to 50 mm. This variety allows adaptors to be tailored to specific construction requirements.

MINI glass adaptor with a 12mm diameter

What shapes and design variations are there?

Glass adaptors are available in both round and square shapes. The head shape can be flat or spherical, while the spacer design depends on the mounting surface. For example:

• For flat surfaces: the spacer is straight.
• For pipe fixings: the spacer has rounded ends, adapting to the pipe shape (diameter 42.4 mm or 33.7 mm).

Square-shaped glass adaptor

Glass adaptor with a flat head on a pipe

Glass adaptor with a spherical surface

How do adjustable and non-adjustable adaptors differ?

Glass adaptors are divided into two categories:

• Non-adjustable adaptors: These have a simpler design without threads in the spacer, where the glass is pressed directly against the supporting structure.

• Adjustable adaptors: These allow adjustment by changing the position of the spacer. For example:

  • A spacer with threads allows adjusting the distance from the structure.
  • A split spacer with a cup, where the cup is attached to the structure, and the spacer's top part adjusts on the cup, ensuring more precise and aesthetic alignment.

Non-adjustable glass adaptor

Adjustable glass adaptor with a threaded spacer

Adjustable glass adaptor with a cup

What additional elements and kits are available?

There are kits available that allow the connection of two glass panels in a straight direction, at a 90° angle, or to railing posts. These kits include connection plates and other necessary elements. Separate components such as heads, spacers, or rubber gaskets are also available.

Glass adaptor kit to connect two glass panels at a 90-degree angle

What material and finish are they made of?

Glass adaptors are primarily made from stainless steel (AISI304 or AISI316). The surface finish can be Satin, polished, or painted. The most popular colors include:

• Black (RAL 9005)
• Gray (RAL 7016)
• White (RAL 9003)
• Gold (matte or polished)

Glass adaptor painted in black (RAL 9005)

Glass adaptor painted gold, Satin

Adjustable and non-adjustable side by side

Frequently asked questions

What sizes of glass adaptor are available?

The catalogue covers diameters from 12 to 70 mm. The smaller ones, 12 to 19 mm, suit plates and lightweight structures; the larger ones, 30 to 70 mm, are for bigger glass structures. Spacer thickness runs from 4 to 50 mm.

How large should the hole in the glass be?

The hole diameter must be at least equal to the glass thickness. In practice leave 2 to 4 mm of margin: if the adaptor seat is 17 mm, an optimal hole is 20 to 22 mm, which makes installation easier and leaves room to adjust.

How close to the edge can the hole be?

The distance from the hole edge to the glass edge must not be less than twice the glass thickness. If the design requires it closer, a notch connecting the hole to the nearest edge must be made to reduce stress concentration.

Which stainless steel grade should be chosen?

The catalogue covers AISI 201 for dry indoor use, AISI 304 for general use and AISI 316 for outdoor, humid and coastal environments. For anything outdoors, choose AISI 316.

Summary

Glass adaptors offer a wide range of sizes, shapes, and materials, making them suitable for both aesthetic and functional purposes. Their versatility ensures that every project can be executed with maximum precision and efficiency.

Practical tips for designing and installing glass structures

1. Appropriate Hole Diameter in Glass

When selecting glass adaptors, it is crucial to pay attention to the required hole diameter in the glass to ensure precise and secure installation. For example, if the seat diameter of the adaptor is 17 mm, the recommended minimum hole diameter would be 18 mm. However, in practice, such a small difference makes accurate installation challenging. Therefore, it is advisable to allow for adjustment options and choose a hole diameter that is at least 2–4 mm larger. In this case, an optimal hole size would be 20–22 mm, which facilitates the installation process and ensures the stability of the structure.

 

 

2. Ratio of Glass Thickness to Hole Diameter

 

The hole diameter in the glass must be at least equal to the glass thickness to ensure the safety and durability of the structure. A hole that is too small can create stress concentrations within the glass, increasing the risk of cracking or breakage.

3. Distance of the Hole from the Glass Edge

 

Tempered glass must be used in load-bearing glass structures to ensure safety and durability. To reduce the risk of breakage during the tempering process, it is crucial to maintain a minimum distance between the hole edge and the glass edge, which should not be less than twice the glass thickness. If the structural design requires the hole to be positioned closer to the glass edge, a notch must be made, connecting the hole to the nearest edge. This helps to reduce stress concentration and enhance the overall strength of the glass.

Klāvs Rubenis & Juris Rubenis, StroFIX

Last updated: 2026-08-17 · Juris Rubenis, Strofix