An insert nut provides a threaded socket

Socket

Socket may refer to:In mechanics:* Socket wrench, a type of wrench that uses separate, removable sockets to fit different sizes of nuts and bolts...

 for a wooden workpiece, similar to a wall anchor. Insert nuts are inserted into a pre-drilled hole by one of two means: screw in and hammer in. In both cases, the external protrusions bite into the wood, preventing the nut from either turning or pulling out.

Insert nuts are advantageous over barrel nut

Barrel nut

A sex bolt, also known as a barrel nut, barrel bolt, Chicago screw or post and screw, is a type of fastener which has a barrel-shaped flange and protruding boss that is internally threaded. The boss sits within the components being fastened, and the flange provides the bearing surface...

s and T-nut

T-nut

A T-nut, also known as a blind nut, is a type of nut used to fasten a wood, particle or composite materials workpiece, leaving a flush surface. It has a long, thin body and a flange at one end, resembling a T in profile...

s, because they can be installed from one side of the workpiece.

Screw-in type

Screw-in insert nuts have an external thread and hex head and are screwed in with an Allen wrench. The screw-in insert nuts come in various sizes and take different screw sizes. For example, a "1/4-20" insert nut will take a 1/4-20 inch bolt. The pre-drilled hole must be as deep as the length of the insert nut plus any portion of the bolt that may be screwed past the end of the nut in the work piece.

Hammer-in type

Hammer-in insert nuts, also known as knock-in nuts, are lined with barbs and are hammered in. They are often made of steel

Steel

Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

, brass

Brass

Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...

 or nylon

Nylon

Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...

. They are designed to work in wood and particle board

Particle board

Particle board, or particleboard , is an engineered wood product manufactured from wood particles, such as wood chips, sawmill shavings, or even saw dust, and a synthetic resin or other suitable binder, which is pressed and extruded...

.