Choosing and Fitting H0, H2 or H3 Mounting Plates: Correct Positioning in the 32 mm Hole Pattern for Concealed Hinges

The height of a cross mounting plate (H0, H2, H3) determines the distance between the concealed hinge and the cabinet side panel, proving decisive for achieving an exact gap pattern on furniture doors.

The correct installation of cupboard doors depends entirely on positioning the mounting plate precisely inside the carcass. Even the highest-precision concealed hinge cannot close a door flush if the counterpart on the cabinet interior wall has the wrong spacer height or is positioned off-centre. Especially on large frontages, such as those found on a modern wardrobe or a floor-to-ceiling double wardrobe, every millimetre of deviation accumulates into an untidy overall look.

This guide is aimed at joiners, fitters, and experienced furniture makers. It covers the technical selection of plate heights, the dimensional standards according to System 32, and exact fixing within the cabinet carcass. For an experienced hand, measuring and mounting a plate takes approximately 5 to 10 minutes.

Technical Foundations: What Do H0, H2, and H3 Mean?

The designations H0, H2, or H3 (often also D0, D2, D3) specify the distance height of the cross mounting plate in millimetres. This height compensates for the thickness of the carcass side panel and defines how far the door overlaps the side panel when closed (the so-called overlay).

The interaction between hinge and mounting plate operates like a precision gear mechanism: if a measurement deviates by even a single millimetre, the mechanism jams or the door sits crooked. Which mounting plate you require depends primarily on the desired application type:

• Full overlay (door sits fully in front of the carcass side panel): A plate with height H0 (0 mm) is generally the standard here, provided typical board thicknesses of 16 mm to 19 mm are used.
• Half overlay (two doors share a central partition): A plate with H0 is frequently used here in combination with a cranked hinge, or a taller height such as H2 or H3 with specific hinge geometries to hit the half overlay accurately.
• Inset (door sits flush within the carcass sides): Depending on the hinge manufacturer and the required reveal, H2, H3, or special wedge spacers are often used here.

When building kitchen cabinetry, such as modern kitchen units, System 32 is the absolute industry standard. This means: the distance between the drill holes is exactly 32 mm, and the front row of holes sits as standard 37 mm away from the front edge of the carcass.

Required Tools and Materials

The following tools are essential for the precise installation of mounting plates inside the carcass:

• Cordless drill/driver with torque clutch
• Screwdriver or driver bit in size PZ2 (Pozidriv) for the adjustment screws on the hinge
• Bradawl (marking awl) for pinpoint marking of drill centres
• Tape measure, ruler, or ideally a precision marking gauge
• Wood drill bit with centring point (Ø 5 mm for Euro screws, Ø 2.5 mm for pilot drilling for chipboard screws)
• Depth stop for the drill bit (prevents drilling right through the carcass side)

Step-by-Step Guide: Positioning and Securing the Mounting Plate

The following instructions assume standard installation using System 32 for a classic full overlay. If the focus is on living room furniture, such as the construction of a TV sideboard or a modern lowboard, gaps calculated precisely to this scheme will deliver the required clean aesthetic.

Step 1: Mark the Setback Line on the Carcass Side

The horizontal position of the mounting plate is standardised. Measure exactly 37 mm inward from the front edge of the carcass side panel. Draw a fine, vertical pencil line. This represents the centre line for the front fixing screws of the cross mounting plate.

Note: For inset doors (inset application), this measurement shifts backwards. It is calculated by adding 37 mm plus the door thickness plus the desired gap (e.g. 37 mm + 19 mm door + 2 mm gap = 58 mm).

Step 2: Determine the Vertical Height

The height of the mounting plate in the carcass must correspond exactly with the height of the 35 mm cup hole in the cabinet door. Measure the distance from the top or bottom edge of the door to the centre of the cup hole (typically around 100 mm). Transfer this measurement to the carcass side panel. Take the vertical reveal into account: if the door requires a 2 mm gap to the top panel, subtract this 2 mm when transferring the mark to the carcass. Mark the intersection on your vertical 37 mm line.

Step 3: Mark Drill Centres and Pilot Drill

The intersection determined in Step 2 represents the exact centre of the mounting plate. Because the plate is secured with two screws spaced 32 mm apart, measure 16 mm upwards and 16 mm downwards from the centre along the 37 mm line. Punch both points firmly using the bradawl.

Now drill the holes:

• If using Euro screws (frequently supplied with pre-assembled plates), drill with a 5 mm wood bit to an exact depth of 13 mm.
• If using traditional chipboard screws (Ø 3.5 mm or 4 mm), pre-drill with a 2.5 mm bit to a depth of around 10 mm to prevent the chipboard from splitting.

Step 4: Screw the Cross Mounting Plate into Position

Position the plate. The arrow marking (if present) must point towards the front edge of the carcass. Drive the screws in using the cordless drill on a low torque setting. The material strips easily if the screws are over-tightened. Tighten the screws for the final half-turn by hand using a PZ2 screwdriver.

Note for alternative hardware: If you are building wall units, for instance to house a wall unit dish drainer, and working with lift-up flaps instead of doors, remember that gas struts for heavy flaps have entirely different fixing specifications and force vectors compared to classic hinges. The 37 mm setback distance does not necessarily apply in such cases.

Step 5: Clip on the Concealed Hinge and Carry Out 3D Adjustment

Once the door is fitted with the hinge cups, place the hinge arm onto the front edge of the mounting plate and snap it into place at the rear with gentle pressure (for clip-on hinges). An audible click confirms it is securely engaged.

Now proceed with fine adjustment via the screws on the hinge arm:

1. Depth adjustment: Loosening the rear screw on the mounting plate slightly (or turning the eccentric cam screw on premium plates) allows adjustment of the gap between the door and the front edge of the carcass. A gap of 1.5 mm to 2 mm is ideal to prevent the door binding against the carcass side when opening.
2. Height adjustment: Mounting plates usually feature slotted holes. Loosening the fixing screws slightly allows the door height to be shifted by roughly +/- 2 mm.
3. Side adjustment (overlay): The front screw on the hinge arm regulates the overlay. Turning clockwise moves the door further over the carcass side (narrowing the gap), while turning anti-clockwise widens the gap.

Only when the gap pattern is completely true all round should modern furniture handles be permanently mounted, as misaligned doors drastically distort the visual alignment of the handles.

Common Installation Mistakes

Incorrect Plate Height Selected If an H3 plate is fitted by mistake instead of an H0 plate for a full overlay on a standard carcass (19 mm side thickness), the closed door will project 3 mm too far away from the carcass edge. The lateral adjustment screw on the hinge is usually insufficient to compensate fully for this 3 mm error, preventing the door from closing flush.

Missing the 37 mm Setback If the plate is mounted at 35 mm or 40 mm, the door either cannot close at all because it binds against the front edge of the carcass, or the gap between the door and carcass becomes so wide that the soft-close damper no longer engages properly.

Torn-Out Screw Holes Especially with melamine-faced chipboard, driving screws without pre-drilling leads to cracking in the coating. If the hole is already stripped, standard chipboard screws will no longer hold. In this scenario, drill out the holes to 5 mm and use dedicated Euro screws, or insert repair dowels.

FAQ – Frequently Asked Questions

Can I combine hinges and mounting plates from different manufacturers? No. The clip mechanisms, hinge arm geometries, and positions of the adjustment screws are manufacturer-specific (e.g. Blum, Hettich, GTV). A brand A hinge cannot be locked securely onto a brand B plate, even if both follow System 32.

What is the difference between a cross mounting plate and a straight mounting plate? The cross mounting plate is the furniture-making standard. It is secured vertically with two screws spaced 32 mm apart. A straight mounting plate (inline plate) is secured horizontally. It is often used on glass display cabinets or in applications where space constraints (such as very shallow carcasses) prevent a cross plate from fitting.

Why can my door not be adjusted far enough to the left or right? If the side adjustment screw has reached its maximum stop and the reveal is still incorrect, you have most likely installed the wrong plate height (e.g. H2 instead of H0) or purchased a hinge designed for the wrong application type (e.g. half overlay instead of full overlay).

How do I secure mounting plates into very thin side panels? For carcass side panels under 15 mm thick, standard Euro screws (13 mm length) are often too long, as the tip could puncture the outer face. In this case, shorter chipboard screws (e.g. 3.5 x 12 mm) must be used. Using an exact depth stop on the drill bit is mandatory here.