Various sizesThere are 7 most common sizes, M3 / M4 / M5 / M6 / M8 / M10 / M12, to meet your daily needs. Excellent material 65Mn metal steel , high quality, extremely strong, anti-corrosion and durable. Locking EffectThe lock washer exerts a spring force between the head and the base plate to secure the hard washer to the thread of the hard bolt in front of the base plate, which increases friction and resistance to rotation. Wide ApplicationWidely used in mechanical equipment, electronic equipment, household appliances and other fields, suitable for artisans, professionals, industries, artisans and decoration. Classified StorageEach size is separated in a storage box for easy access and storage.