T-nut (pronged T-nut / tee nut with prongs)

T-nut with prongs (爪付ナット / pronged T-nut)

This is an insert-type nut used for wood or similar base materials to create a female thread for bolts.

It has a cylindrical body with a flat base, and prongs (爪) at the corners that penetrate into the base material. These prongs secure the nut in place and prevent rotation or pull-out.

Installation method:
The nut is inserted into a pre-drilled hole in the base material and then fixed by hammering from the back or pressing it into place.