DOJA INDUSTRIAL nuts and bolts are ideal for wood fastenings. Their hexagonal head makes them an easy-to-use tool. These screws are perfect for both amateurs and professionals, as they have a wide range of applications in carpentry, construction, plumbing, and 3D printing. They are of high quality and have a zinc-plated finish. This pack includes 30 units of 8 x 40 mm screws. We offer a 100% money-back guarantee in case of any problem with our product.