Designing a double extension drawer

You are planning to manufacture a double extension drawer:

design a double extension drawer

  • for a transfer airlock in a laboratory booth,
  • on an assembly line
  • to feed a manufacturing robot
  • on a specific vehicle layout
  • or any other sector that requires a bilateral opening?

You are planning to install a drawer with robust and reliable telescopic slides. Perhaps you have already read our article explaining how to choose the ideal slide for your project? And you want to add this option that allows access to a drawer on either side of the fixed part?

CHAMBRELAN has the solution! We have designed telescopic slides with double extension!

design a double extension drawer


1-Functionality of the double extension slide

2 – Locking device

3 – Examples of double extension slides

4 – Options

1 – Designing a double extension drawer: functionality

Double extension is an option that exists on some models in our telescopic slide range. It allows for development on both sides of the fixed part. Although it is considered an option, we are able to manufacture these models quickly in our factory in Le Havre. It is simple to make on partial extension telescopic slides, more complicated on total extension slides. Note that it is not available on 4-element over-extension models. Double extension slides have no restraints in the closed position. You can provide for this possibility in your design, or use our ergonomic slam lock handle for drawers with double extension.

A – Length of the double extension slide

In order to satisfy the needs of more customers, we produce and stock our range of telescopic slides in lengths from 150 mm up to 2 metres! We can also manufacture bespoke slides to suit customer drawings. Double extension slides with total extension have maximum recommended lengths of up to 1200 on heavy duty models type RA5DD and RA7DD; for longer lengths, upgrade to E1700DD or E1902DD.

B – Extension of the double extension slide

This double extension option can only be configured on partial extension or total extension telescopic slides. Thus, if you need to install a drawer with a pair of 500 mm long folded slides, they will expand to the following lengths

      • Partially with 2-element slides,
      • Totally, about 500 mm,

On either side of the fixed drawer!

C – Load

The load capacity of a slide with bilateral extension is the same as that of the same standard model. For example, a 500mm long RA5R slide will support a load of 174kg per pair for major axis, and will support the same load in RA5DD length 500 with double extension.

D – Material

As with our standard range of telescopic slides, we offer the double extension option on ball bearing slides in :

      • Zinc plated steel,
      • Anodised aluminium,
      • Stainless steel…

E – Environment

These double extension slides are commonly used in the following sectors:

      • Laboratory access airlocks
      • Assembly lines (drawers for mechanical parts or for tools)
      • Vehicle or train fittings

But you can also find our bilateral slides at post office or bank counters … In the current health crisis, fittings with double extension telescopic slides may be ideal to avoid physical contact and thus respect hygiene measures!

2 – Designing a double extension drawer: locking device

your double-extension drawer is installed ; But the double extension slides do not have an integrated central retainer.

To help you, CHAMBRELAN has designed and produced one of the ergonomic slam lock handle for double extension installations.

The ergonomic slam lock handle for double extension drawers locks your installation in a central position. To unlock the drawer, open and close it from either side, simply press the button in the centre of the handle to access the contents of the drawer. It’s easy to use! The kit is delivered complete for one drawer (2 handles). See our assembly tutorial here.

DHFDD Slam lock handle - Double extension drawer

3 – Designing a double extension drawer: examples


The RA7DD double extension zinc-plated steel telescopic slide is one of the most frequently used ball bearing slides in our range of total extension slides. It is available in lengths from 250 to 2000 mm. It supports loads up to 355 kg for major axis and 212 kg for mouting on minor axis. This telescopic rail is very resistant to vibration, making it a popular choice for vehicle mounting! It is also available in a stainless steel version and even in double extension for similar lengths and loads.

RA7DD Telescopic slide - Double development - Steel - Full Extension


This anodised aluminium slide has a double development and is ideal for low to medium loads. For office drawer assemblies for administration or banking environments, this slide can still support up to 60 kilos per pair for major axis. Lightweight and space-saving, it will enable you to install it easily and functionally. This slide is available in lengths from 250 to 1000 mm. It has a partial extension and develops about 75% of its folded length. For the same slide profile designs, it can be supplied in galvanised steel or stainless steel. It will then have a much higher load capacity (up to 160 kg per drawer)!


This stainless steel ball bearing slide, from our range of telescopic “I” slides, is ideal if you need to support ultra heavy loads! Up to 900 kg with major axis! This ball bearing slide is 100% expandable, allowing an extension of up to 2 metres! Sometimes required in pharmaceutical or laboratory environments, this runner will find its place in transfer SAS, clean rooms or drawers for the storage of medicines. An equivalent exists in galvanised steel in reference E1012 with the same load capacities and dimensions!  Like our other CHAMBRELAN references, this slide can withstand a temperature range from -20° to 80°.


Although double extension is already an option on some telescopic slides, we can offer you some additional alternatives to meet your needs:

    • Length of the double extension slide made to measure
    • Special treatment (hard anodising, zinc-nickel treatment, etc.)
    • Mounting of stainless steel balls in place of steel balls,
    • Assembly of the slide without grease or with special greases ( alimentary), high temperature grease, teflon free …)

Contact us to discuss your project!

Find what you are looking for

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…

Contact us