Furniture Legs & Table Legs — Selection & Installation

Furniture legs and table legs are structural load-bearing components that transfer the weight of carcases or tabletops to the floor, establish the working height, and compensate for uneven surfaces. In professional furniture making and DIY projects, they serve both structural and ergonomic purposes. Choosing the correct components determines the stability of a cabinet against tipping, ensures a table remains free from vibration, and protects floor coverings.

This guide covers technical specifications, material differences, and fitting procedures for furniture legs and table legs. It is designed for DIY enthusiasts and fitters looking to build furniture from scratch or reliably replace existing hardware.

Types and Materials in Furniture Construction

The construction method and material of a leg determine its mechanical load capacity. Whilst concealed kitchen plinths focus purely on functionality, visible elements must also withstand lateral forces, such as those generated when moving furniture.

Metal and Steel

Metal is the benchmark for heavy carcase systems, solid wood tables, and upholstered furniture. Metal furniture legs provide high torsional rigidity. Steel table legs are especially suited to freestanding tables because they safely transfer bending moments, caused by lateral pressure on the tabletop, into the floor base. Steel tubes are typically welded and subsequently finished.

Surface Finishes

The surface finish protects the core material against corrosion and defines the overall aesthetic.

• Electroplated: Chrome furniture legs are produced via an electroplating bath. They are exceptionally scratch-resistant and suitable for humid environments such as bathrooms, provided the base layer remains undamaged.
• Brushed/Satin: Satin furniture legs feature a slightly textured, low-reflection finish. Fingerprints and fine scratches are far less noticeable on satin compared to high-gloss chrome.
• Powder-Coated: A thermally cured paint coating. Black furniture legs or white table legs are usually powder-coated. The typical coating thickness is 60 µm - 100 µm, providing robust impact protection.

Profiles and Geometries

Geometry influences the contact area. Cylindrical tubes distribute the load evenly across their cross-section. Square furniture legs, due to their straight edges, often provide a broader contact surface with the mounting plate and complement clean, linear carcase designs.

Technical Selection Criteria

Sizing legs must not rely solely on visual preferences. The physical properties of the furniture piece and the conditions of the room dictate the required specifications.

Load Capacity and Weight Distribution

The load capacity is specified in kilograms (kg) per leg. When calculating requirements, add the dead weight of the furniture (carcase, shelves, front panels) to the maximum intended load. For example: a sideboard made of chipboard weighs 40 kg. It will be loaded with books weighing approximately 60 kg, giving a total weight of 100 kg. Distributed across four legs, this represents a static load of 25 kg per component. However, because furniture is also subjected to dynamic loads (leaning on it, moving it), a safety factor of 1.5 to 2 should be included. In this scenario, each leg should support at least 40 kg - 50 kg.

Height Adjustability and Levelling

No floor is perfectly flat. Levelling is essential to prevent stress within the carcase, which can lead to misaligned door gaps or sticking drawers. Adjustable furniture legs feature an integrated threaded mechanism inside the base. Turning the floor glide typically allows for continuous height adjustment of 10 mm - 20 mm. Adjustable table legs also use this principle, often with a heavier-duty thread to eliminate wobbling on uneven tiles or floorboards.

Thread Types and Fixing Methods

There are two primary methods for securing legs to furniture:

1. Screw-on Plate (Flange): The leg is permanently welded to a square or round metal plate. This plate is screwed directly beneath the bottom panel of the furniture with four to six screws, offering the highest stability against lateral forces.
2. Threaded Stud: The leg features a protruding threaded bolt on the top (typically M8 or M10). The furniture piece requires a matching internal thread, which is achieved by inserting an insert nut (threaded insert) or a tee nut (prong collar nut) into the wooden base.

Applications in Furniture Construction

Hardware requirements differ significantly depending on the category of furniture.

Kitchen and Plinth Assembly

In kitchens, concealed plinth legs made from high-strength ABS plastic are standard. They support substantial loads, including the carcase, stone worktops, and appliances. Standard heights range from 100 mm - 150 mm. Compatibility with plinth clips is essential here, allowing the front fascia panel to be clipped on without tools.

Sideboards, Chests of Drawers, and Upholstered Furniture

Visible design legs are used for these items, with heights typically ranging between 50 mm - 200 mm. Sufficient ground clearance simplifies cleaning (including for robotic vacuum cleaners) and gives the furniture a lighter visual appearance. For wide chests of drawers (from approximately 1200 mm width upwards), a fifth central support leg must be fitted beneath the base panel to prevent sagging.

Desks and Dining Tables

Table legs require a design with high flexural strength. A table leg without a rigid flange connection is like a shallow-rooted tree; it will yield at the first lateral force. For freestanding tops without a stabilising apron (subframe under the top), table legs with large mounting plates (e.g. 100 mm x 100 mm) must be used. Standard desk heights require leg lengths of approximately 710 mm. Adding a 25 mm to 30 mm thick tabletop yields the standard ergonomic height of around 740 mm.

Installation and Fixing Techniques

Proper installation is vital to prevent screws from stripping and to ensure the furniture stands securely.

Tools Required

• Cordless drill/driver
• Wood drill bits (typically 3 mm for pilot holes, 8 mm or 10 mm for inserts)
• Crosshead screwdriver (PZ or TX)
• Folding rule and pencil
• Spirit level

Step-by-Step: Fitting with a Screw-on Plate

1. Positioning: Mark the leg positions on the underside of the furniture. The distance from the outer edge should be symmetrical (frequently inset by 20 mm - 50 mm from the edge).
2. Pilot Drilling: Pilot drilling is mandatory in dense materials (MDF, solid wood) or coated boards. Use a 3 mm drill bit and drill approximately 2 mm shallower than the screw length. Use a depth stop (or tape on the bit) to avoid drilling through the base panel.
3. Fixing: Position the leg and secure it with wood screws. For a standard 18 mm base panel thickness, use screws measuring 4 x 15 mm or 4 x 16 mm (countersunk or pan head, depending on the plate's holes).
4. Levelling: Stand the furniture upright. Use a spirit level and adjust the levelling glides until the carcase is completely true and plumb.

Step-by-Step: Fitting with a Threaded Insert Nut

When fitting legs with an M8 threaded stud:

1. Drilling for the Insert: Drill a vertical hole into the base panel. For an M8 insert, a 10 mm or 11 mm drill bit is generally required, depending on the external thread diameter of the insert.
2. Driving the Insert: Screw the insert nut flush into the wood using an Allen key or a wide flat-head screwdriver.
3. Attaching the Leg: Screw the furniture leg hand-tight into the metal thread. This connection provides high tensile strength and allows repeated disassembly without damaging the wood.

Frequently Asked Questions (FAQ)

How do I calculate the required load capacity for furniture legs? Add the unladen weight of the furniture to the maximum anticipated load. Divide this figure by the number of legs (usually 4). Multiply the result by a safety factor of 1.5. For a 100 kg piece of furniture, each of the four legs should support at least 37.5 kg.

What screw length do I need for 18 mm chipboard? The screw must not penetrate through the board. With a mounting plate thickness of approximately 2 mm, 16 mm of material remains. Use screws with a maximum length of 15 mm or 16 mm (e.g. 4 x 15 mm).

What is the standard thread size for screw-in furniture legs? In European furniture construction, M8 (8 mm metric thread) and M10 (10 mm) are the industry standards. M8 is sufficient for light to medium loads, whilst M10 is commonly used for heavy tables or sofas.

Can adjustable legs completely level very uneven floors? This depends on the adjustment range. Most standard legs provide a tolerance compensation of + 15 mm to + 20 mm. For steeper floor gradients, packing shims or specialist levelling legs with extended threaded spindles must be used.

How far from the edge should I install table legs? To prevent interference with chair legs and maintain balanced proportions, table legs are usually set back 50 mm to 100 mm from the outer edge of the tabletop. On very thin tops, this inset also reduces leverage on the outer perimeter.

What should I do if a screw hole in the wood has stripped? Standard wood screws will not grip in a stripped hole. Drill the hole out to 8 mm or 10 mm and insert a glued wooden dowel, or fit an insert nut with a metric internal thread to establish a new, strong anchor point.

Do I need a centre support leg for a 1600 mm wide sideboard? Yes. Across spans from roughly 1000 mm to 1200 mm upwards (depending on base panel thickness), furniture bases tend to sag under load. A fifth leg installed centrally beneath the bottom panel safely supports the weight of the central carcase sections.

Related Categories and Guides

To complete your furniture project and plan your build thoroughly, explore these hardware fittings from our range:

• Overview of all furniture legs for carcases and cabinets.
• Specific metal furniture legs for heavy load requirements.
• Adjustable table legs for ergonomic desks and uneven surfaces.
• Sturdy steel table legs for dining table construction.
• Additional interior fittings: wall-mounted wardrobe rail.