40pcs Wood Furniture Threaded Screws. Internal Thread Insert Type: 1/4"-20, this is not a metric nut, the thread inside the nut is different, please match this type when selecting accessories. Material: High hardness and high quality carbon steel. Usage: Use the appropriate drill bit to pre-drill/drill a well-sized hole (the depth is 1-2mm longer than the furniture screw), and then use a suitable 6mm internal hex tool to screw in. Tip: If the furniture wood is very hard, please enlarge the screw hole. Applications: These furniture screws are wear-resistant and very durable. Suitable for hardwood/solid wood furniture, for furniture combinations. Features of the insert nut: These threaded inserts are inserted into a pre-drilled hole by screwing into the wood, in this case the outer protrusions bite into the wood, preventing the nut from turning or coming out. Suitable for: Easy to install and with good stability, has a good effect in furniture combination, suitable for all furniture