Full Extension Drawer Runners as an Alternative to Grass — Compatible & Suitable

A full extension drawer runner allows the drawer to be pulled 100% out of the cabinet carcass, unlike a single extension runner which stops at around 75%.

Full Extension Runner as an Alternative to Grass — Compatibility and Technical Features

When existing runner systems need replacing during furniture assembly or repairs in kitchen and interior fittings, fitters and joiners often search for suitable replacement parts. Mechanical components in furniture construction are subject to industry-wide standardisation across many areas. Therefore, a full extension drawer runner from the furnica range is an excellent technical alternative to Grass, provided the installation dimensions and hole pattern match.

When replacing defective runners or upgrading from a basic single extension to a convenient full extension runner, functionality takes centre stage. Changing a runner rail is much like changing a tyre on a vehicle: wheel size and pitch circle diameter must precisely match the suspension, regardless of the printed brand name.

What to Look for Regarding Compatibility?

To ensure a new runner functions smoothly as a replacement for Grass or other established systems, four essential technical parameters must be checked:

• Nominal length: This is the length of the closed runner, which usually corresponds to the depth of the drawer. Common dimensions in furniture making range from 250 mm up to 800 mm. For standard kitchen cabinets, lengths such as 500 mm are frequently required. For smaller carcass depths, 400 mm drawer runners or 300 mm drawer runners are used.
• Hole pattern: Most modern carcass systems are based on System 32. This means the drill holes in the carcass side have a 32 mm spacing from one another, starting at a defined distance from the front edge (usually 37 mm). A runner intended to be compatible with Grass drillings must support this line boring system.
• Installation width: For side-mounted runners (such as ball bearing runners), the side clearance between the drawer side and the carcass interior wall is crucial. The standard dimension here is very often 12.7 mm per side.
• Load capacity: The load rating of the runners is specified in kilograms (kg). Standard runners typically carry between 25 kg and 45 kg. For workshop units or extremely wide pull-outs, a heavy duty drawer runner system is required, capable of taking loads from 80 kg to over 130 kg, even at extreme lengths of 1200 mm, for example.

Suitable Drawer Runners for Replacement

Depending on the furniture construction, different runner types are used. To identify the correct replacement part, the design type must first be determined.

Undermount Runners

In high-grade kitchens and living room furniture, the mechanism is often mounted invisibly beneath the drawer base. Such undermount drawer runners engage with special clips at the front or are secured using hooks at the rear panel. If you are looking for such a runner as an alternative to Grass Dynapro, ensure you check the exact internal drawer width as well as the drawer side thickness (usually 16 mm).

Ball Bearing Runners

The ball bearing runner is a robust telescopic slide screwed to the side of the drawer. It runs on small steel balls and offers high lateral stability. This type is very flexible to retrofit, as it is screwed directly to the carcass side panel and the drawer side.

Roller Runners

An older yet still widely used system is the roller runner. Here, a plastic roller runs inside a powder-coated metal profile. When replacing such a runner, a roller drawer runner set offers a quick and accurately sized solution. It is often sufficient to replace only the carcass part of the runner if the nominal length matches exactly.

Mechanism: Soft-Close vs Handleless Fronts

Upgrading runner profiles is often accompanied by a desire for greater convenience. Here, a strict distinction must be made between two opposing mechanical principles:

Soft-close damping: This mechanism gently brakes the drawer over the final centimetres of travel and pulls it silently into the cabinet carcass. At furnica you will find soft close drawer runners as well as models with self-closing mechanisms. These systems require the drawer to feature a handle so it can be pulled open against the damper resistance.

Push-to-open (tip-on): For handleless fronts, the opposite mechanism is required. Pressing the front triggers a mechanical spring that pushes the drawer open a short distance. Push to open drawer runners do not feature a damper, as the momentum is needed to engage the spring upon closing. Soft-close and push-to-open cannot be combined within a purely mechanical runner.

Installation and Retrofitting the Runners

Fitting a new full extension runner requires precision, but can be easily carried out using standard tools.

Tools Required

• Cordless screwdriver
• Matching bits: PZ (Pozidriv) or TX (Torx)
• Tape measure / folding rule
• Pencil
• Spirit level or try square
• Matching chipboard screws (e.g. 3.5 mm x 16 mm) or Euro screws (for System 32)

Step-by-Step Installation

1. Removal: Remove the old drawer from the carcass. Unscrew the old carcass runners and, if present, the runners on the drawer sides.
2. Checking dimensions: Check whether the new runners are compatible with Grass hole positions in your carcass. Measure the distance from the carcass front edge to the first fixing hole. On standard fittings, this is often 37 mm.
3. Fitting the carcass runner: Align the new runner horizontally. Use Euro screws if you are using the pre-drilled 5 mm holes of the System 32 line boring. For individual positions, use chipboard screws.
4. Fitting to the drawer: For a ball bearing runner, separate the inner profile via the release lever and screw it centrally onto the drawer side. For an undermount runner, screw the locking clips underneath the front of the drawer base.
5. Insertion: Guide the drawer horizontally into the carcass until the mechanism audibly clicks into place. Check the alignment gaps and, if necessary, adjust using the adjustment screws (height/tilt) on the locking clip.

If you are reconfiguring the entire interior layout of a kitchen, runner dimensions depend on the unit width. For a standard base unit, a 60 cm kitchen cabinet pull-out fitting is suitable. The internal width inside the carcass is exactly 564 mm when using 18 mm thick side panels.

Frequently Asked Questions (FAQ)

Can I replace a single extension runner with a full extension runner? Yes, this is generally straightforward. It is important that the nominal length is identical and the side installation width (often 12.7 mm) matches the new runner. The hole pattern in the carcass may need slight adjustment if the new runners do not use the exact same grid.

How do I determine the correct length for my drawer runner? Measure the length of the old, completely closed runner or the external depth of your drawer. Runners are available in standard increments (e.g. 400 mm, 450 mm, 500 mm). Select the dimension that matches your drawer depth or is a maximum of 10 mm shorter.

Are furnica runners compatible with Grass drawer sides? Furnica runners are suitable as a replacement for Grass when it comes to the pure sliding action and the dimensions (System 32, internal clearance) match. However, with double-walled metal drawer sides (drawer box systems), care must be taken to ensure the profile connection of the carcass runner fits the metal side profile exactly. For solid timber drawers, replacing undermount runners is significantly more flexible.

What does the load capacity rating mean? The load rating in kilograms indicates how much weight the runner can permanently support when fully extended. This includes the dead weight of the drawer plus its contents. For a cutlery drawer, 25 kg is sufficient; for deep pan drawers, runners rated to at least 35 kg to 45 kg should be selected.