Description These nut expansion screws are designed for securing hollow metal cavities and hollow doors. The unique nut design ensures a firm grip, making them ideal for various applications. The screws are ideal for use in plasterboard, drywall, and other hollow wall structures, providing a reliable and sturdy hold. Features -Color:Silver -Material:Carbon steel -Size:2.30X1.10X1.10cm/0.90X0.43X0.43in -Thread: M4 -Outer Diamter: 8 mm -Inner Diameter: 4 mm -practical material: made of carbon steel, these nut expansion screws are robust and resistant to deformation. -Ideal for hollow walls: ideal for securing various workpieces in hollow walls, providing a stable and reliable hold. -Expansion design: the expansion nut design ensures that the anchor bolt expands on both sides when the screw is tightened, increasing grip strength -Stable fastening: the fastening components are firm and stable, ensuring they do not easily loosen, making them ideal for thin sheets -Easy installation: the hollow dowels are heavyduty and easy to install, saving time and effort Package list: 15 x hollow door fixing anchors