Finding and Reordering Drawer Runners by Height: H17, H27, H35, H45 & H53

Drawer runners are mechanical guiding systems made of metal or plastic that enable the smooth opening and closing of drawers inside furniture carcasses. When a drawer sticks, catches, or the ball bearings fall out, the runner needs replacing. When identifying the correct replacement part, you will inevitably come across designations such as H17, H27, H35, H45, or H53. These values define the exact profile height of the runner in millimetres and are the most important criterion for ensuring compatibility when replacing fittings.

This technical guide is aimed at fitters, joiners, and experienced DIYers. It breaks down the different profile heights, explains the mechanical differences between runner types, and provides the necessary parameters to determine the exact matching runners for furniture building or repair projects.

The H-System: Understanding Drawer Runner Heights

The designation "H" followed by a number refers to the vertical height of the runner profile in millimetres. This dimension is primarily relevant for ball bearing runners mounted to the side of the drawer. The height directly correlates with the load capacity and stability of the fitting.

To reorder the correct runner, the height of the old runner must be measured accurately whilst fully closed.

H17 (17 mm Profile Height)

The H17 runner is a miniature slide. It is frequently manufactured as a partial extension runner. Due to its low profile height and a typical installation width (thickness) of around 10 mm, it is often recessed into a side groove on the drawer (groove mounting). Typical applications include keyboard trays under desks, small spice pull-outs, or very shallow drawers for stationery and jewellery. The load capacity is low and usually lies below 10 kg.

H27 (27 mm Profile Height)

Runners with a height of 27 mm are the standard for light to medium-duty applications. They typically require a side installation clearance of 10 mm to 12.5 mm. They are commonly found in light chests of drawers, bathroom units, or bedroom wardrobes. The load capacity is around 15 kg.

H35 (35 mm Profile Height)

The H35 runner represents the middle tier. It is more robust than the H27 and is often used where an H45 cannot be fitted due to space restrictions. The load capacity is around 20 kg to 25 kg. It is available as both a partial and a full extension runner.

H45 (45 mm Profile Height)

The H45 is the absolute industry standard for side-mounted ball bearing runners. When modern furniture construction uses full extension drawer runners, this is the profile used in the vast majority of cases. The standard installation width is 12.7 mm (half an inch). These runners offer high lateral stability and load ratings from 30 kg to 45 kg. They are the premier choice for kitchen drawers, workshop trolleys, and heavy-duty office pedestals.

H53 (53 mm Profile Height)

Profiles with a height of 53 mm fall into the heavy-duty category. Due to solid materials and wider ball cages (installation width often 19 mm), they achieve load capacities of 80 kg, 100 kg, or more. Anyone looking for heavy-duty drawer runners for vehicle conversions (campervans), tool chests, or platform storage beds relies on the H53 profile.

Runner Types: Ball Bearing, Roller, or Undermount?

Alongside the profile height, the type of runner determines running performance and mounting position.

1. Ball Bearing Runners

Ball bearing runners consist of interlocking steel profiles held apart by tiny steel balls housed in a ball cage. They are almost exclusively side-mounted (rarely fitted flat, which drastically reduces load capacity). Ball bearing runners operate with extreme precision, have minimal side play, and are available across all H-heights.

2. Roller Runners

Roller runner drawer slides are a simple, tried-and-tested system used for decades. They consist of two epoxy-coated steel profiles with plastic rollers (typically nylon). Mounting is carried out along the bottom edge of the drawer. They tolerate slight inaccuracies in cabinet construction better than ball bearing runners, but offer less lateral stability and are almost always a partial extension runner.

3. Undermount Runners

For high aesthetic demands, undermount drawer runners are used. The mechanism is mounted entirely out of sight beneath the drawer base. The drawer sits on top of the runner and is often secured with special locking clips. This system requires precision drawer manufacturing, as tolerances are very tight.

Full Extension vs Partial Extension: Defining Extension Travel

A key technical feature is the extension travel relative to the installed length.

• A full extension runner opens to 100%. The drawer box can be pulled completely clear of the cabinet carcass. This allows unrestricted access right into the rearmost corners. This is achieved using a three-part telescopic profile (cabinet profile, intermediate profile, drawer profile).
• A partial extension runner only opens to around 75%. Part of the drawer remains inside the cabinet. The profile is usually only two-part. Partial extensions are mechanically simpler and tolerate higher lateral loads at lower profile heights.

Determining Nominal Length: Measuring Accurately

Runners are classified by their nominal length (installed length in the closed state). Lengths are generally graded in 50 mm increments. The nominal length of the runner must never exceed the internal clear depth of the cabinet carcass.

• For very shallow bathroom cabinets or bedside tables, drawer runners 250 mm or drawer runners 300 mm are frequently used.
• Standard chests of drawers mostly utilise drawer runners 350 mm or drawer runners 400 mm.
• In kitchen base units, drawer runners 450 mm and drawer runners 500 mm represent the standard sizes.
• For deep workbenches or platforms, drawer runners 550 mm, drawer runners 600 mm, or even longer variants are used.

Important when measuring: Measure the length of the metal runner whilst completely closed, not the depth of the wooden drawer.

Mechanical Convenience Features

Modern fittings feature integrated mechanisms that change the operational feel. These features are design-dependent and generally cannot be combined arbitrarily.

Soft-Close (Damping)

Drawer runners with soft-close catch the momentum of the drawer over the final few centimetres. An integrated hydraulic damper cushions the movement, while a small spring pulls the box gently and quietly into its final position. This prevents drawer fronts from slamming shut.

Self-Closing

Drawer runners with self-closing feature a tension spring at the rear. When the drawer is closed, the mechanism engages over the final centimetres and actively pulls the drawer shut. Unlike soft-close, there is no damping cylinder here. The drawer is pulled closed, but not gently decelerated.

Push-to-Open (Tip-On)

For handleless furniture fronts, push-to-open drawer runners are required. Pressing against the front tensions a spring and releases a catch; the drawer pops open by a few centimetres.

Please note: Soft-close and push-to-open are opposing mechanisms. Soft-close pulls the drawer shut and dampens it, whereas push-to-open pushes the drawer outward. Combining both systems within a purely mechanical runner is technically complex and not found on standard hardware fittings.

Installation and Technique: Fitting Runners Correctly

Replacing a runner is like changing a tyre on a car: the original manufacturer brand is secondary, provided the hole pattern and dimensions match exactly. If the installation clearance (the gap between drawer side and internal carcass wall) and the profile height (e.g. H45) match, a defective model can be replaced with an alternative brand.

Tools Required

• Cordless drill/driver or screwdriver
• Bit size PZ2 (Pozidriv)
• Tape measure or folding rule
• Spirit level or set square
• Bradawl or small awl

Fixing Materials and Hole Patterns

Fixing is almost always carried out using System 32. This established furniture construction grid specifies a hole spacing of 32 mm and a setback of 37 mm from the front cabinet edge. Runners feature corresponding slotted and round holes.

For mounting inside a wooden carcass, use countersunk chipboard screws, typically 3.5 mm or 4 mm in diameter (length usually 16 mm). Alternatively, for pre-drilled 5 mm holes, special flat-headed Euro screws are used, which cut directly into the chipboard.

Installation Steps (Ball Bearing Runner)

1. Separate: Disengage the ball bearing runner by pressing the small black plastic release lever. The inner profile (drawer member) can now be pulled completely out of the outer profile (cabinet member).
2. Mount cabinet profile: Screw the wide outer part to the inside wall of the cabinet. Use only the slotted holes initially for fine height and depth adjustments.
3. Mount drawer profile: Screw the narrow inner part centrally onto the outside face of the drawer.
4. Insert: Pull the ball cages in the cabinet profile fully forward. Position the drawer horizontally and slide the inner profiles into the ball cages. Close with light pressure until the locking mechanism audibly engages.

FAQ – Frequently Asked Questions About Drawer Runners

Can a ball bearing drawer runner be repaired? No. If the steel balls fall out of the cage or the profile is bent, the mechanism is irreparably damaged. Forcing balls back in leads to rough running and damages the remaining bearings. The runner must be replaced entirely.

How do I measure runner length correctly? Always measure the metal runner in its fully closed state. Do not measure the extension travel, nor the depth of the wooden drawer. The resulting figure (e.g. 450 mm) is the nominal length.

How much installation clearance does an H45 runner require? An H45 ball bearing runner generally requires an installation clearance (gap between carcass and drawer) of 12.7 mm per side. In total, the drawer must be 25.4 mm narrower than the internal clear width of the cabinet carcass.

Can I replace a roller runner with a ball bearing runner? Yes, this is generally possible, but requires practical DIY skill. The installation clearance must match (often 12.5 mm per side). Furthermore, the mounting position changes from the bottom edge (roller runner) to the lateral centre (ball bearing runner). New fixing holes must be measured accurately.

Can I replace a partial extension with a full extension runner? Yes. If you have an H45 partial extension fitted, you can easily replace it with an H45 full extension runner of the same nominal length. The drilling pattern (System 32) is identical across standardised fittings.

Which screws do I need for installation? Use countersunk chipboard screws (PZ or TX drive) with a diameter of 3.5 mm or 4 mm. For standard carcass panels (16 mm or 18 mm chipboard), the length should be around 16 mm to prevent screwing through the side panel.

Related Categories & Lengths

If you require specific dimensions for very deep cabinet designs, suitable heavy-duty and full-extension runners are available in the corresponding length categories:

• Drawer runners 650 mm
• Drawer runners 700 mm
• Drawer runners 750 mm