What is a Plug Cutter?

A plug cutter is a wood working or joinery tool used to cut wooden plugs for use as filler pieces to repair imperfections or damage in wooden items where the use of wood putty is undesirable. Such tools are manufactured for use in a hand drill or drill press and have cutting edges designed for hard or soft wood. The plugs produced by a plug cutter have a chamfered or beveled edge for easy insertion and are tapered to ensure a secure fit, making them a superior option to the use of wood putty. Plug cutters can be re-sharpened and typically come in sets of different sizes for both hard and soft wood.

A plug cutter is a hollow tubular tool with a cutting edge machined into one end and a spindle or shaft on the other. The shaft is inserted into the chuck of an electric hand drill or drill press and the tool used to cut a circular groove into wood. The central “pillar” on the inside of the groove is then snapped or cut off and used as a filler plug. The internal profile of the plug cutter is such that the plugs are slightly tapered with a beveled edge. These plugs are coated with wood glue and tapped into place in the hole to be filled.

Using screws, nails, and other metallic fasteners in the construction of wooden furniture is a strong and long lasting option but leaves aesthetic aberrations that are often difficult to disguise. The same applies to knotholes and other natural imperfections. Wood putty can also be a quick and easily solution to mask or fill unwanted holes but it does have several drawbacks such as shrinkage and cracking.

A plug cutter to produce filler plugs can be a far better option and allows for long lasting, almost invisible repairs. When constructing new wooden items, plugs may be cut from the same timber used for the construction; this allows for a match in color and grain that makes the repair work very difficult to detect. Wooden filler plugs also expand and contract with the rest of the piece and thus do not crack or fall out with time as is the case with wood putty.

Plug cutters are usually made of 62c high carbon steel and can be sharpened when blunt. Some plug cutter designs incorporate an automatic plug ejection system though most rely on the plug being manually snapped off with a screwdriver or cut off with a saw. As plug cutters don’t have a central guide or spur, the most accurate and consistent results will be achieved using a drill press. Plug cutters are usually bought in sets which include various sizes of cutter suitable for both hard and soft wood types.