Spring lock washers,Square section wire. Designed to prevent nut & bolts from loosening. Metric Size M2,M3, M4, M5, M6, M8, M10, M12, M14, M16. Manufactured from A2 stainless steel for increased corrosion resistance. Specification: Material:304 Stainless Steel Color:Silver Size: M2:3.30.49mm/0.130.02inch M3:5.10.8mm/0.200.03inch M4:6.41.1mm/0.250.04inch M5:81.3mm/0.310.05inch M6:9.81.6mm/0.390.06inch M8:132.1mm/0.510.08inch M10:152.56mm/0.590.10inch M12:183.1mm/0.710.12inch M14:223.62mm/0.870.14inch M16:254.12mm/0.980.16inch Package Includes: 1 Set of Spring Coil Washers(50 Pieces M2/M3,45 Pieces M4,40 Pieces M5,35 Pieces M6,30 Piececs M8,25 Pieces M10,20 Pieces M12,18 PiecesM14,12 Pieces M16) Note: Please allow 0.5-1 inch difference due to manual measurement. (1 inch=2.54cm) The color of the actual items may slightly different from the listing images due to different computer screen, thanks for your understanding.