Features: - Type E Recessed Fitting Insert Nut. - The E-Type has no flange and can be set below the surface of the material or on curved surface - To install Type E Insert Nuts, simply screw the self-tapping body into the base material. The unique external thread ensures positive locking and offers strong resistance against pull-out due to torsion or vibration. - Insert Nuts provide a strong, permanent thread for wood and wood based sheet materials.