Description: The washer is a thin disk-shaped plate with a hole in the middle that is normally used to distribute the load of a threaded fastener, such as a screw or nut. Other uses are as a spacer, wear pad, pre-load indicating device, locking device, and to reduce vibration. High-quality bolted joints require hardened steel washers to prevent the loss of pre-load after the torque is applied. Washers are also important for preventing galvanic corrosion, particularly by insulating steel screws from aluminum surfaces. Features: Made of high quality steel material, these flat washers are sturdy and has long service. Flat washers can spread a load, and prevent damage to the surface being fixed, and insulate steel screws from surface. They can be used as a spacer, wear pad, pre-load indicating device, locking device, and to reduce vibration. Flat washer is applied when the hole is a larger diameter than the fixing nut. There are many different sizes in this set. Each set includes many flat washers that can be used for a long time, so you don't have to run to hardware store looking for washers for quite a while. Specifications: Material: A3 steel Type: Flat washer Color: Silver Size & Quantity: M3*150pcs M4*150pcs M5*200pcs M6*200pcs M8*150pcs M10*50pcs Weight: 446g(approx.) Package Includes: 900 x Washers