These bolts have a size of 42x8mm. Please confirm if the size meets your requirements before purchasing. These bolts are suitable for installation in 8mm holes and can be used in conjunction with 8mm drill bits during installation. These bolts are made of plastic and iron, which are sturdy and come with harpoon threads. After installation, they can effectively secure the target. These bolts are suitable for industries such as woodworking and cabinets. When the connector is tightened, the double cone in the bolt will expand the sleeve and push the thread into the wood. The stronger the fastening force, the more secure the connection. Package includes: 50x Spreading Bolt, Manufacturer: EMSea