Which extension for my drawer slide?

You have chosen to install telescopic slides in your project. What type of extension should you choose? This is the main question you should ask yourself when consulting the CHAMBRELAN range of telescopic slides!

Definition :

What we call the extension, or development is the length of movement of the front face of your moving part (usually a drawer). It is not the length of the fully extended slide! In order to choose the drawer slide that best suits your project, it is essential to take into consideration this need for extension. The extension is always compared to the folded length of the slide.

CHAMBRELAN, as a specialist of telescopic slides manufacturing, offers three types of extension: partial extension, total extension, or over-extension.

To help you choose your telescopic slide, we have written a guide explaining how to select the ideal telescopic slide! Depending on the load to be supported, the environment, or the need, the extension of the slide will make the difference for your study. The applications are numerous: from a simple sliding of a 200 gram desktop keyboard, to the extraction of a 500 kg battery box in a railway train, to the deployment of a platform on a vehicle or the installation of a telescopic walkway … CHAMBRELAN will adapt to all your projects!

We also invite you to discover on our Youtube channel a video summarising these three types of extensions!

Youtube Chambrelan channel


This guide explains what you need to know about extending a ball bearing slide!

Contents :

1 – Partial extension sliders

2 – Full extension drawer guides

3 – Over-extension drawer slides

1 – Partial extension sliders

CHAMBRELAN telescopic slides with partial extension include 2 beams. They are available in anodised aluminium, galvanised steel or stainless steel. These ball bearing slides are very compact. They offer a partial development for environments with a reduced space requirement. The rear part of the drawer will remain inside the fixed drawer cabinet. This part is therefore more difficult to access.


These telescopic rails are suitable for light to extra heavy loads. For this purpose, reinforcing balls included inside the slides, allow to take up the crushing and the torques applied on the slide.

According to the specificities of your project, you can add options to the telescopic slide :

    • Locking system: lock out, lock in, lock out and in
    • double extension,
    • vertical mounting…

This type of slide has a reduced deflection under load!

Finally, for the same load and material, partial extension telescopic slides are the most economical in our catalogue.

Do not hesitate to consult us for more information!

A – Examples of applications :

With a stroke of approximately two thirds (2/3) of the folded length, our partial extension ball bearing slides can be found in applications such as:

B – Examples of partial extension telescopic slides

The ST38 stainless steel ball bearing slide is one of the most compact slides in our range! With its dimensions of 9.6 mm wide and 28 mm high, it is appreciated in environments requiring very little space! Generally, it is adopted in medical environments, for outdoor applications, in clean rooms or laboratories.

In addition, it meets the following standard characteristics:

      • Folded length of : 250 mm to 900 mm in standard version
      • Length of the development of : 165 mm to 600 mm in standard version
      • Maximum load capacity per pair of slides: 85kg on major axis or 40kg on minor axis under the drawer
      • Vertical mounting possible without prior modification

Optional :

You will also find in our range of partial extension slides in galvanised steel: the R71 heavy-duty slide. Resistant, it integrates reinforcement balls that take up the crushing as well as the torsional moments. It can therefore be mounted on minor axis.

Intended for heavy loads, it is available with the following standard characteristics:

      • Folded length of : 200 to 1700 mm in standard version
      • Length of the development of : 80 to 1140 mm in standard version
      • Maximum load capacity per pair of slides: 280 kg on major axis or 120 kg on minor axis under the drawer

Optional :

Highly appreciated in industrial environments, this steel slide will also be suitable for mounting in a vending machine or in an on-board vehicle!

2 – Total extension drawer slide

The 3-beams ball bearing slides offer a total extension of 100% of their folded length. Compared to partial extension slides, they include an intermediate beam to provide additional extension.

Due to their 100% development, these slides can be integrated into all types of applications. This is the most common development chosen in projects.

They are available in three versions: galvanised steel, stainless steel or anodised aluminium. They can withstand light, moderate, heavy or even ultra-heavy loads of up to 1500 kg per drawer! As with the two-beams telescopic pull-outs, there are many options available:

    • locking system,
    • double extension,
    • Disconect option..

We invite you to consult us to find out more!

A -Application examples

Our telescopic slides with total extension can be integrated into many applications, including

B- Examples of telescopic slides with total extension

This CHAMBRELAN stainless steel telescopic slide meets all the needs of our customers. It is available with various options, leaving a wide choice of possibilities! It has the following features:

      • Folded length of : 250 mm up to 1600 mm in standard version
      • Extension length of : 275 mm up to 1615 mm in standard version
      • Maximum load supported per pair of slides 176kg on major axis or 67kg on minor axis mounted under the drawer

Optional extras :

Designed for ultra heavy loads, this telescopic rail E1020 made of  galvanised steel can support up to 1500kg when mounted on major axis !

It is part of our I-shaped, also called double T-shaped, manufacturing range. Robust and resistant, it is the perfect solution for difficult working conditions! Its opening is synchronised: a sequential opening of the bems reduces the opening force of the slide under load!

Find out more about this slide and its options:

Standard equipment :

      • Closed length and stroke of : 500 to 2000 mm
      • Maximum load on major axis for a pair of slides: 1.5 tons!

optional :

      • Vertical mounting
      • Hardening of raceways
      • Mounting in a high temperature environment

3-Over-Extension :

CHAMBRELAN also offers Over-Extension telescopic slides.


Couliises acier à billes à super extension

These ball bearing slides are made of 4 beams and have a stroke of 150% of their folded length. These models are available in either stainless steel or galvanised steel, and can support heavy loads of up to 700 kilos!

Options equivalent to other types of extensions are possible:

    • Locking system,
    • Synchronisation of the opening of the beams,
    • Vertical mounting,
    • Use in high temperatures…

It’s up to you: CHAMBRELAN adapts its design to your projects… To discuss it, it’s here.

A – Examples of applications :

When our customers consult us for a ball bearing slide with super extension, generally it is for the following needs:

      • Opening a battery tray (of a vehicle or machine) for maintenance and repair,
      • Lifting platform for cleaning, maintenance or assistance,
      • Telescopic walkway for operator passage,
      • Racks in electronic cabinets, for access to connections
      • Payment systems, for changing the reels of receipts or ticket reels
      • Removal of the protective hood of a transport vehicle (train or plane),
      • Easy handling of generator sets,
      • Winch extensions…

The environments and applications are wide and only depend on your project!

B- Example of over-extension telescopic slides

The ST558 will fulfil you if you are looking to move a heavy load over a long length.

Thanks to its various options, particularly in terms of locking, you will find below the details of this slide:

Standard :

      • Closed length from 300 mm to 1200 mm
      • Development length from 470 mm to 1830 mm
      • Maximum load supported by a pair of slides: 116 kg on major axis or 30 kg when mounted on minor axis underneath the drawer

Options :

It is made of hardened drawn steel and zinc-plated, which contributes to its solidity and resistance! In addition, reinforcing balls are integrated into the back of the slide strands to withstand crushing and torsional forces!

Its standard features are:

      • Folded length from 500 to 2000 mm
      • Stroke length from 750 to 3000 mm
      • Maximum load supported per pair of slides: 450 kilos on major axis or 190 kilos on minor axis
      • Synchronisation of beams

Optional extras :

      • Vertical guillotine type mounting
      • High temperature

There are many fields for CHAMBRELAN telescopic ball bearing slides! Depending on the need and the load to be supported, the extension of the slide will be different. If you have any doubts : do not hesitate any more and contact us! We will be delighted to help you with your project!

Find what you are looking for

    *Required information

    A question ?

    1.Technical specifications?

    • Assembly plan
    • Availability
    • Load capacity…

    2.Application fields of our industrial products?

    • design of a custom-made telescopic slide
    • selection of a model according to its load capacity…