High quality four-prong T-nuts Standardized metric thread for easy assembly Size: M4 x 8 mm Package contains 50 parts Material: Galvanized steel A T-nut is often used to hold a wood, particleboard, or composite part in place while leaving a flush surface. It is a coupling piece that cooperates with metric screws. Size: M4 x 8 mm. The package contains 50 pieces.