The washer is a thin, disk-shaped plate with a central hole, commonly used to distribute the load of a threaded fastener such as a screw or nut. Other applications include use as a spacer, wear pad, preload indicator, locking device, and vibration reducer. High-quality bolted joints often require hardened steel washers to maintain preload after torque application. Washers help prevent galvanic corrosion by electrically isolating dissimilar metals—for example, steel screws from aluminum surfaces. This set of flat washers is made from high-conductivity copper, offering excellent electrical and thermal conductivity. Flat washers help distribute load, protect the surface being fastened, and provide electrical insulation between steel fasteners and other materials. They are suitable when the mounting hole diameter exceeds that of the fastener. This set includes multiple sizes for versatile applications. Specifications: M5 × 9 × 1 mm — 30 pcs M6 × 10 × 1 mm — 30 pcs M6 × 12 × 1 mm — 20 pcs M8 × 12 × 1 mm — 30 pcs M10 × 14 × 1 mm — 30 pcs M8 × 14 × 1 mm — 20 pcs M12 × 16 × 1 mm — 25 pcs M14 × 18 × 1 mm — 25 pcs M12 × 18 × 1.5 mm — 20 pcs M16 × 20 × 1.5 mm — 20 pcs M16 × 22 × 1.5 mm — 15 pcs M20 × 26 × 1.5 mm — 15 pcs Package includes: 280 copper flat washers 1 plastic storage box Note: Color may vary slightly due to screen settings. Dimensions are subject to a tolerance of ±1–3 mm.