Provide a strong long thread for wood. They are installed by simply screwing the self tapping body into the material. The unique external thread strong resistance against pull out and the unique head prevents splitting of surfaces and driving the inserts in too far. Features - Color: As Shown. - Material: Zinc Alloy. - Size: 17.00X9.50X2.00 cm/ 6.68X3.73X0.79 inch. - Made of quality zinc alloy, wear-resistant, not easy to rust, good mechanical properties. - Unique self-tapping designed external thread protrusions, contribute to tapping. - Bite with good tensile resistance, can effectively prevent the nut from either turning or pulling out. - Can be screwed in with a key wrench(not included), easy to install and use. - The flanged head prevents splitting of the surfaces and driving the insert in too far. Package list: 330 x Nuts