How to Fit Undermount Drawer Runners: Step-by-Step Guide for the 32 mm Hole Pattern

An undermount runner is fitted concealed beneath the drawer base and standardly uses the System 32 hole pattern with a 32 mm hole spacing and a 37 mm setback from the front edge for cabinet fixing.

Proper installation of concealed runners requires precision when drilling the cabinet carcass and specific preparations on the drawer box itself. Unlike side-mounted runners, the runner carries the load from underneath, making exact box dimensions essential. This guide is aimed at joiners, fitters, and skilled tradespeople who want to integrate runners into furniture carcasses to industrial standards. Fitting takes around 20 to 30 minutes per drawer once materials are prepared.

Required Tools and Fixing Materials

For clean installation within the system grid, you will require the following tools and fixings:

• Cordless screwdriver with suitable driver bits (PZ2 for chipboard screws or TX15 / TX20 depending on the screw head)
• Wood drill bits (Ø 5 mm for Euro screws, Ø 3 mm for pre-drilling in solid wood)
• Folding rule or tape measure
• Marking gauge or combination square for accurate scribe lines
• Spirit level
• Drilling template for System 32 (optional, but extremely helpful)
• Fixing materials: Euro screws (usually 6.3 x 13 mm) for existing 5 mm hole patterns, or chipboard screws (3.5 x 15 mm) for direct screw fastening into timber.

Matching runner hardware can be found in our range of undermount drawer runners.

Mandatory Drawer Box Requirements

Before installing the runners in the cabinet, the drawer box must be built specifically for undermount installation. A standard drawer designed for side-mounted ball bearing runners cannot be used here.

1. Base Inset: The drawer base must not sit flush with the bottom edge of the side panels. It must be recessed upwards (typically by 12 mm to 15 mm) to create clearance for the runner.
2. Rear Notching: The back panel of the drawer must feature cutouts along its bottom edge. The runner slides through these notches.
3. Drill Hole for the Hook: A hole (typically Ø 6 mm) must be drilled in the rear panel (or the back of the drawer side). The rear fixing hook of the runner engages here to secure the drawer.
4. Internal Width: The internal width of the drawer must precisely match the internal cabinet width and runner thickness. Always refer to the manufacturer's technical data sheet for exact deduction dimensions.

Step-by-Step Guide: Fitting with the 32 mm System

The following guide assumes a standard cabinet carcass that either already contains a line of holes or is to be drilled manually.

Step 1: Determine the Position of the Cabinet Profiles

The cabinet profile is the section of the runner screwed directly to the carcass side. In System 32, the first vertical line of holes is positioned exactly 37 mm from the front edge of the carcass. Measure the required installation height for your drawer. The drilling height determines where the drawer base will sit. Mark the fixing positions on both inside faces of the carcass. Pay strict attention to ensure that the marks on the left and right are at the exact same height.

Step 2: Screw the Cabinet Profiles in Place

Position the left cabinet profile. Align the front fixing hole of the runner with the 37 mm drill hole. Use Euro screws when fastening into pre-drilled 5 mm hole lines. This provides the highest pull-out resistance. If screwing directly into un-drilled sheet material (chipboard or MDF), pre-drill with a 3 mm drill bit and use chipboard screws (3.5 x 15 mm). Fasten the front fixing point first, level the runner with a spirit level, and insert the remaining screws into the rear fixing points. Repeat this process for the right-hand side.

For narrow cabinets or specialist bathroom furniture installations, short variants such as 250 mm drawer runners are often used.

Step 3: Fit the Front Locking Devices to the Drawer

The locking device (also known as a front catch) connects the wooden drawer box to the steel runner. It is screwed flush into the front underside corners beneath the drawer base on the left and right. Turn the drawer upside down. Place the left-hand catch flush against the front sub-front and the left side panel. Fasten it with two or three chipboard screws. Mirror this on the right-hand side. These locking devices contain the adjustment levers for height and side alignment.

Step 4: Insert and Engage the Drawer

Pull the mounted cabinet profiles slightly forward out of the cabinet. Place the drawer box onto the runners from above. The engagement mechanism functions like a ski binding – place the drawer on the tracks and push it horizontally backwards with light pressure. As you do this, the rear hooks of the runners slide into the pre-drilled holes in the back panel. Push the drawer fully home until the front locking devices audibly engage with a click into the runners. Pull gently to ensure the drawer is securely locked onto the fittings.

Step 5: Adjust the Front Gaps (Fine Tuning)

To achieve uniform front gaps across your furniture units, high-quality undermount systems feature built-in adjustment directly on the locking device.

• Height Adjustment: A small thumbwheel or slider on the locking device usually allows the front to be raised by up to +3 mm.
• Side Adjustment: Many models allow side-to-side adjustment of +/- 1.5 mm to align side reveals.
• Tilt Adjustment: Typically located at the rear of the runner or on the rear hook to align tall fronts parallel to the carcass.

Mechanical Variants: Soft-Close and Push-to-Open

When selecting runners for your project, consider the intended opening and closing motion of the front. These mechanisms are integrated into the runner and require no additional components on the cabinet carcass.

A soft-close mechanism dampens the drawer over the final few centimetres of travel, pulling it shut smoothly and silently. This protects the material and prevents slamming, which is particularly crucial under heavy loads. Suitable options can be found in our soft-close drawer runners selection.

The opposite operating method is push-to-open technology (also known as tip-on). This is used exclusively for handleless furniture fronts. Light pressure on the closed front releases an internal spring, opening the drawer slightly so it can be pulled open by hand. These systems rely on different mechanical damper concepts. Matching options are listed in our push-to-open drawer runners range.

These two systems must not be confused or combined, as mechanical self-closing and touch-release mechanisms would block one another.

Common Installation Mistakes and How to Avoid Them

• Incorrect Depth Hole Setback: If the first screw is not located at exactly 37 mm, the drawer front will not sit flush with the front edge of the cabinet. It will either protrude or sit too far back inside the unit.
• Non-Parallel Mounting: If the runners are spaced 500 mm apart at the front but 502 mm at the back, the drawer will bind when moving. Always use a marking gauge or measure precisely from the carcass inner walls.
• Rear Hook Disengaged: If the drill hole in the rear panel is missing or misaligned, the runner cannot support the back of the drawer. The drawer will tip downwards when extended.
• Ignoring Load Capacity: Standard runners are usually rated for 30 kg. For wide kitchen pan drawers, this is often insufficient. In these situations, heavy-duty drawer runners with load capacities of 40 kg to 70 kg should be used.

Frequently Asked Questions About Undermount Installation

What is the difference between full extension and single extension? A full extension runner allows the drawer to slide out 100% from the carcass, giving unhindered access to the entire contents right to the back. A single extension runner (partial extension) extends to around 75% due to its design. For deep units, full-extension drawer runners are always recommended.

Can I simply replace standard side-mounted roller runners with undermount runners? No. The drawer box dimensions differ fundamentally. A side-mounted runner requires clearance between the drawer side and carcass wall (typically 12.7 mm per side). An undermount runner requires clearance underneath the base. If you wish to switch runner types, you will generally need to build or source completely new drawer box systems.

Which runner length do I need for a 60 cm deep kitchen cabinet? The nominal length of the runner depends on the drawer box depth. For a standard kitchen cabinet with 560 mm internal clear depth, a 500 mm or 550 mm nominal length runner is typically fitted. If you are retrofitting complete internal storage kits, consider dedicated modules such as a 60 cm kitchen cabinet pull-out fitting.

Why is the locking device not clicking into place? This usually happens if the drawer has not been pushed far enough back, or if the rear hook on the runner has missed the drill hole in the drawer back panel. Remove the drawer completely, check the rear holes, and slide the drawer back in horizontally with a firm, steady motion.