T Nuts
Zinc Plated Steel

3 & 4 Prong
T-Nuts consist of a flat flange with a cylindrical barrel which is threaded to allow a bolt to engage the Tee Nut. Prongs extend from the flange to grip the material into which the T-Nut is being inserted.
Drill a pilot hole for the body into wood, then hammer the T-Nut in place.
T-Nuts must be installed so that the screw or bolt pulls the nut into the wood.