Alternative to Blum Legrabox: Comparing Dimensions, Nominal Length, and 32 mm Hole Pattern

March 10, 2026

A drawer box system combines the drawer runner directly with the side panel and requires precise drilling according to System 32 in the cabinet carcass. Anyone seeking a functional alternative to the Blum Legrabox in furniture construction must examine the technical specifications of the fittings closely. In professional interior fitting and kitchen installation, the exact nominal length, drilling pattern, and load capacity dictate whether a drawer system operates smoothly inside the cabinet.

This guide is aimed at installers and joiners planning and fitting double-walled drawer systems. It highlights the essential dimensional specifications that must be adhered to and compares how different runner types perform side by side.

Key Purchasing Criteria for Drawer Systems

When switching from an established system to a compatible alternative, the physical parameters of the cabinet carcass and the planned drawer runners must align.

Dimensions and Nominal Length (NL)

The nominal length defines the depth of the drawer and generally matches the length of the runner. It is the most critical dimension during planning. The cabinet carcass must always be slightly deeper than the nominal length of the runner to accommodate the back panel and closing mechanism. Standard drawer systems work with incremental sizes that typically increase in 50 mm steps. For standard base kitchen units, a nominal length of 500 mm is frequently selected, whilst drawer runners 400 mm or shorter are commonly used for shallower bathroom furniture or office cupboards.

Hole Pattern and System 32

A precise hole pattern is the foundation of cabinet making; deviating here leaves the entire construction unstable. System 32 is the industry standard for furniture manufacturing. It defines the distance between drill holes (32 mm) as well as the distance from the front edge of the carcass to the first row of holes (usually 37 mm). The drill hole diameter for Euro screws is typically 5 mm. Any Legrabox alternative must support this hole pattern so that carcass runners can be mounted without supplementary routing or drilling work.

Load Capacity and Dynamic Loading

The load capacity is stated in kilograms and always refers to the combined weight of the drawer itself and its contents. Standard runners usually handle 30 kg to 40 kg. For wide pan drawers in the kitchen or workshop units, heavy-duty drawer runners are required to support dynamic loads of 50 kg to 70 kg without distorting the runner profile.

Overview of Types and Runner Options

Double-walled metal drawer systems are characterised by straight internal and external side walls. The actual mechanism remains concealed beneath the drawer base.

Undermount Runners vs Side Mounting

Modern drawer box systems rely almost exclusively on an undermount runner. Here, the runner sits invisibly beneath the drawer base and connects directly to the metal side wall. This protects the mechanism from dirt and maximises the usable width of the cabinet. Undermount drawer runners form the technical core of any Legrabox alternative.

Extension Type: Full Extension and Single Extension

A full extension runner pulls out 100% from the carcass, providing complete access to the rearmost section of the drawer. A single extension runner stops at approximately 75% to 80% of the nominal length due to its design. For modern kitchen and furniture making, full extension drawer runners are used almost exclusively, as they significantly improve ergonomics.

Motion Technologies: Soft-Close and Opening Assistance

The opening and closing mechanisms must not be confused:

Soft-Close: Integrated damping cushions the momentum of the drawer over the final few centimetres, pulling it shut gently and quietly. Soft-close drawer runners achieve this via a compact oil or gas piston damper fitted in the carcass runner.
Push-to-Open: A mechanical release that enables handleless fronts. Applying light pressure to the front triggers the drawer to pop open. This mechanism functions in the opposite manner to a damped self-closing mechanism.

Which System for Which Application? (Selection Guide)

Choosing the correct drawer side and runner depends on the specific area of use.

For storing heavy items in wide units: For a 60 cm kitchen unit pull-out, select a system with a dynamic load rating of at least 40 kg and an undermount full extension runner. The drawer side height should measure at least 150 mm to retain pots and pans securely.
For handleless front designs in living areas: Opt for a system with mechanical push-to-open assistance. Ensure precise front gap adjustment (typically a 2.5 mm to 3 mm trigger path).
For shallow drawers in bathrooms or offices: A low drawer side height (approx. 80 mm to 90 mm) is ideal for cosmetics or stationery. For shallow cabinet depths, choose drawer runners 300 mm. A load capacity of 25 kg to 30 kg is usually sufficient here.

Installation Notes: Fitting with System 32

Properly installing an alternative drawer box system requires a cross-line laser or try square, a cordless screwdriver, and Euro screws (Ø 5 mm) or standard wood screws (Ø 4 mm).

Position the carcass runners: Screw the runners to the internal side walls of the cabinet. Following System 32, the frontmost screw sits exactly 37 mm back from the front edge of the carcass.
Assemble the drawer sides: Screw the metal sides to the cut-to-size wooden base (usually 16 mm thick chipboard).
Insert the back panel: Fix the wooden back panel using the dedicated rear panel brackets of the metal sides.
Attach the front panel: Screw the front fixing brackets to the drawer front, then clip them into the drawer sides without tools.
Adjustment: Correct the panel alignment using the integrated adjustment screws inside the drawer sides (height, side, and tilt adjustment).

FAQ – Frequently Asked Questions About Drawer Systems and Alternatives

Can I combine Blum Legrabox carcass runners with drawer sides from other manufacturers? No. The fixing points, front-panel clip mechanisms, and runner locking catches are proprietary. An alternative must always be purchased and fitted as a complete set (runner, drawer sides, and front fixing brackets).

What does nominal length mean for a drawer runner? The nominal length (NL) denotes the standard installation length of the carcass runner and defines the required length of the metal drawer side. It dictates how deep the drawer extends into the cabinet.

How do I combine push-to-open with soft-close damping? By default, these two mechanical systems are mutually exclusive. However, certain manufacturers offer synchronisation units that combine a push release with a damped self-close action. These require dedicated carcass runners.

What hole pattern is required for a concealed runner? Professional undermount runners use System 32. The drill holes in the cabinet side have a 5 mm diameter, a vertical pitch of 32 mm, and start horizontally 37 mm behind the front edge of the carcass.

Is a 16 mm thick drawer base strictly necessary? Most modern drawer box systems are designed specifically for bases and back panels made from 16 mm thick board. If thicker board is used, the edges around the side panel rebate must be rebated down to 16 mm.

Matching Products & Categories for Furniture Making

To identify the correct dimensions for your project, refer to the carcass depth and the required weight rating. The following categories provide technical guidance: