Leveling foot

Overview

A leveling foot has a threaded stem and a pad on a ball joint so it sits flat on a tilted floor. The stem screws into a threaded insert or T-nut in the underside of a leg, a plinth board or the bottom of a cabinet. Turning the pad (or the hex at the top of the stem) lengthens or shortens the leg. It is the cleanest way to stop a tall case rocking on a floor that is not flat.

Types and sizes

Metric M8 or M10 stems are the norm; sold in a range of stem lengths, 25 to 60 mm (1 to 2-1/2 in). The pad is nylon or plastic to protect a floor, or felt-faced for wood. For the stem to turn, the thread must be in a metal socket: a Threaded insert or a Machine screw and T-nut. Do not rely on thread cut into the wood itself.

Where it is used

Contemporary and workshop pieces: kitchen and bathroom cabinets, plinths, shelving, and cabinets with a recessed plinth where you cannot reach the foot with a spanner. Period pieces were traditionally shimmed with a folded wedge, not adjusted.

Choosing and sizing

Allow four feet (one per corner) and three for a table you want to stand on a bad floor. Choose the foot by the weight per foot, not the total, and add margin: a loaded case may carry twice its empty weight. Heavier pieces want M10 and a pad that is wider than the stem by a factor of four.

Installation

1. Mark the foot position at least 30 mm (1-1/4 in) in from each edge of the leg or base so the socket is not close to the edge.
2. Drill the socket hole: for an M8 threaded insert, typically 10 mm (3/8 in) in hardwood, 12 mm (1/2 in) in a thicker leg, to a depth 3 mm (1/8 in) more than the insert.
3. Drive in the insert with a bolt and nut, flush with the leg bottom.
4. Screw in the foot and adjust so the weight is carried on all four; check with a spirit level front-to-back and side-to-side.

Wood movement and species

An insert set into end grain holds best in dense hardwood. In softwood or an end-grain leg, add a glued base block or use a full-length bolt. Movement across the grain of a leg is small; the insert must be set square so the foot does not lean.

Common mistakes

• Insert driven crooked: the foot sits on a tilt; use a guide block.
• Stem too long: it carries the load on a long lever and bends. Use the shortest stem that gives the range.
• Foot too small for a heavy case: the pad crushes a soft floor.

Related

• Threaded insert and Machine screw and T-nut: the sockets.
• Cup caster: when the piece must move, not just stand level.