System 32 (Line Boring) vs. Custom Drilling: Cabinet Making Concepts Compared

System 32 is a standardised construction principle in furniture making featuring a continuous hole spacing of 32 mm, whereas custom drilling relies on precisely calculated, point-by-point fixings without a visible grid.

Choosing between a standardised line of holes and custom drilling is one of the most fundamental questions when constructing cabinet carcasses. Both approaches define how fittings such as hinges, runners, and shelves are mounted inside a cabinet. System 32 functions like a railway network — strictly standardised and universally compatible — while custom drilling provides a tailored route for a precisely defined piece of furniture.

What is System 32?

System 32 is the global industrial standard for cabinet construction. It is based on a fixed grid dimension that specifies the positioning of all drill holes on the carcass side panels. Almost all modern furniture fittings are aligned with this standard.

The technical constants of the system are:

• The vertical distance from hole centre to hole centre is exactly 32 mm.
• The distance from the first vertical row of holes to the front carcass edge is standardly 37 mm.
• The diameter of the drill holes is typically 5 mm (occasionally 3 mm for delicate fittings).
• Fastening the fittings is usually done with special Euro screws that seat precisely into the 5 mm drill holes.
• Fittings are mounted cleanly into this grid.

This grid allows you to fit all hardware without repeated measuring when building a modern wall unit or kitchen cabinet. A cruciform mounting plate for a concealed hinge fits into the grid just as easily as the guide runner for drawers.

What is Custom Drilling?

With custom drilling, a continuous grid is completely dispensed with. Drill holes are only positioned where they are strictly necessary for the specific configuration of the furniture.

The maker calculates the position for each fitting separately. When a runner rail needs to be fitted, the height is measured out and the rail is screwed directly into the un-drilled side panel using wood screws (usually with a PZ or TX drive). This approach is frequently used when building a premium modern chest of drawers or bespoke one-off pieces where the interior layout will not be altered after completion.

Core Differences Compared

The choice between the two concepts influences the entire workflow — from planning to final assembly.

• Planning effort: System 32 requires very little calculation. Once the grid is established, the positions for hardware emerge automatically from the manufacturer specifications. With custom drilling, every distance — such as when installing complex drawer systems — must be manually calculated and marked out.
• Flexibility after assembly: A carcass with a continuous line of holes can be modified at any time. Shelves can be repositioned in height, and additional drawer runners can be retrofitted. A custom-drilled carcass is static. Anyone wishing to make alterations later must measure and drill again.
• Interior cabinet aesthetics: This is where custom drilling shines. A minimalist modern wardrobe interior looks much calmer and more refined when the side panels are smooth without unused 5 mm holes.
• Tooling and manufacturing: To drill an accurate grid, a drilling jig for routers, a dedicated drilling guide, or a CNC machine is essential. Otherwise, inaccuracies will accumulate. Custom drill holes can be achieved using a standard tape measure, a marking gauge, and a cordless drill.

Which Concept Suits Which Scenario?

The decision depends heavily on the intended purpose of the furniture and your usability requirements.

When System 32 is the right choice: Whenever versatility is needed. In kitchen cabinets, modular shelving units, or office furniture, shelves frequently need to be adjusted to accommodate different folder or appliance heights. Here, the grid system is ideal, allowing the use of shelf supports or glass shelf supports with a 5 mm pin that can be repositioned without tools.

When custom drilling is superior: In furniture with a fixed, unalterable purpose. A modern lowboard for media equipment or a modern wooden wall unit with fixed flaps and pull-outs does not require height adjustability. In these cases, unused holes detract from the overall look. Custom screw placement is also necessary for very narrow components where the 37 mm front edge setback cannot be maintained.

FAQ – Frequently Asked Questions About Drilling Concepts

Which drill bit is required for System 32? Typically, a specialised dowel drill bit or lip and spur bit with a centring point and a 5 mm diameter is used. This ensures clean, tear-out-free hole edges in coated chipboard.

Can System 32 fittings also be installed using custom drilling? Yes. Almost all modern fittings, such as hinges or drawer runners, feature smaller holes alongside the 5 mm holes for Euro screws. These allow fixing with standard chipboard screws (typically 3.5 mm or 4 mm diameter) at individually calculated positions.

How deep do the holes for the line of holes need to be drilled? For inserting shelf supports or short Euro screws, a drilling depth of 13 mm to 15 mm is usually sufficient. In material thicknesses of 18 mm or 19 mm, you must not drill through under any circumstances, making a depth stop on the drill bit indispensable.

What is the difference when mounting hinges? With grid drilling, the hinge mounting plate is screwed directly onto the line of holes (37 mm from the front edge). With custom assembly, the position of the plate must be marked out manually depending on the desired reveal and the overlay of the door.