Internal Drawers as an Alternative to Blum Antaro — Compatible and Matching

An internal drawer is a drawer system concealed behind a cabinet door, seamlessly integrated into existing kitchen cabinets using undermount runners or a metal box system.

When planning or upgrading a kitchen, joiners and fitters frequently face the task of making base cabinet storage space more efficient. Instead of using shelves where the rear area is difficult to reach, internal pull-out drawers are the ideal solution. When expanding an existing system or replacing defective components, a suitable alternative to Blum Antaro is often required. A smooth installation demands precise knowledge of carcase dimensions, runner types, and the correct hole pattern.

In this technical guide, you will learn what matters for compatibility, which measurements are critical, and how retrofitting is carried out professionally in practice.

Compatibility: The Foundation of Cabinet Fittings

An internal drawer system must be matched precisely to the clear internal width and depth of the carcase. System 32 acts as an invisible coordinate system during carcase planning, defining the exact positioning of the runner tracks through a fixed hole spacing of 32 mm.

To ensure that the selected pull-outs fit as an alternative to Blum systems, the following parameters must strictly be checked:

1. External Carcase Width vs Clear Internal Width: The nominal width of a unit (e.g. 60 cm) always refers to the external dimension. For runner installation, the side panel thickness is critical. With a wall thickness of 16 mm, the clear width is 568 mm; with 18 mm, it is 564 mm. The drawer sides and back panels must account for this difference.
2. Clear Carcase Depth: The depth of the cabinet dictates the maximum length of the runner. For standard kitchen base units, runners with a nominal length of 450 mm or 500 mm are most commonly used.
3. Hinge Position: Because the drawer is installed behind a hinged door, the runner must not collide with the concealed cup hinge. Spacer blocks (packing pieces) often need to be fitted to pack out the drawer runner on the hinge side.

Matching Runners for Standard Kitchen Cabinets

Depending on the cabinet width, the requirements for stability and runner technology vary. High-quality undermount drawer runners are fitted invisibly beneath the drawer base and provide high lateral stability comparable to systems such as Blum Antaro.

For unrestricted access to all cabinet contents, a full extension is essential. Unlike a single extension, which leaves around a quarter of the drawer inside the cabinet, a full extension drawer runner can be pulled out 100%.

Choosing the correct system depends on the standard width of the base unit:

• Narrow Larder Cabinets and Alcoves: A kitchen cabinet pull-out for 30 cm width is outstanding for spices, bottles, or storage jars. Exact guidance is vital here, as narrow, deep drawers tend to tilt under uneven loads.
• Medium Storage Spaces: The kitchen cabinet pull-out for 40 cm is the standard size for internal cutlery drawers or smaller pots.
• Wide Pan and Pot Cabinets: With a kitchen cabinet pull-out for 60 cm, the weight load increases significantly. Close attention must be paid to the dynamic load capacity of the runners. Standard runners carry around 30 kg. For heavy cast-iron pans or stacks of plates, the runner should be rated for 40 kg to 50 kg. If this is insufficient, switching to heavy-duty drawer runners is necessary.

Damping Technology and Mechanics

When customers look for a replacement for Blumotion, the focus is on integrated soft-closing damping. This mechanism ensures that the drawer is decelerated over the final few centimetres and closed smoothly and silently.

In hardware engineering, this is known as soft-close. A fluid-damped cylinder (hydraulic damper) absorbs the kinetic energy while a tension spring pulls the runner into its final position. Soft-close drawer runners are now the benchmark in high-grade furniture making.

Important for technical consultation: Soft-close must never be confused with push-to-open. Push-to-open drawer runners are designed for handleless fronts and eject the drawer when pressure is applied to the front. Combining both mechanisms within one runner is technically complex and requires dedicated synchronisation rods. For a classic internal drawer behind a hinged door, only soft-close damping is relevant.

Installation and Retrofitting in Base Units

Retrofitting an internal drawer is a routine task for experienced DIYers and fitters, provided the preparation is accurate.

Required Tools

• Cordless drill/driver
• Bradawl or centre punch
• Rule and pencil
• Engineer's square
• Chipboard screws (e.g. 4 x 16 mm with PZ or TX drive)

Installation Steps

1. Mark Dimensions: Mark the position of the cabinet runners on the interior sides of the cabinet. If an existing System 32 hole pattern is present, Euro screws can be driven directly into the 5 mm drill holes.
2. Check Hinge Clearance: If the runner is fitted at the height of a hinge, a spacer block (usually 25 mm thick) must be screwed between the carcase side and the runner so the drawer does not strike the hinge when pulled out.
3. Fit Runners: Screw the cabinet runners horizontally. The setback from the front edge of the cabinet is usually 2 mm or 37 mm for standard undermount runners (depending on the system).
4. Assemble Drawer Box and Base: Screw the drawer base (usually 16 mm chipboard) to the metal drawer sides and the wooden rear panel.
5. Attach Internal Front Panel: Instead of a standard furniture front, clip a dedicated internal front panel (usually made of aluminium or matching decor board) onto the front brackets of the drawer sides.
6. Insert and Adjust: Place the assembled drawer onto the extended runners and push it in until the locking catches engage with an audible click. Fine adjustment for tilt and height is carried out via the adjustment dials under the base or inside the drawer side.

Frequently Asked Questions (FAQ) Regarding Compatibility

Can I retrofit any base unit with an internal drawer? In principle, yes, provided the clear internal width and carcase depth match the dimensions of the drawer system. Ensure that no water or gas pipework at the rear of the cabinet obstructs the space required for the runners (often 450 mm or 500 mm installation depth).

Are drawer dampers compatible with Blum hinges? The damping mechanism of the internal drawer and the damping of the cabinet door function entirely independently. If you have a door with a soft-close full overlay hinge, you can fit a soft-close internal drawer behind it without any issues.

Which hinge is recommended for cabinets with internal drawers? To prevent the internal drawer from catching on the opened door when pulled out, the door must swing completely clear of the internal opening. A standard hinge with a 110° opening angle often still protrudes into the carcase space. For cabinets with internal drawers, a zero-protrusion hinge with an opening angle of 155° or 165° is strictly recommended.

How do I determine the correct runner length? Measure the clear internal depth of your carcase from the front edge to the back panel. Deduct roughly 10 mm to 15 mm for clearance. For a carcase depth of 510 mm, ideally choose a runner with a 500 mm nominal length.