A black oxide Schnorr safety washer is a type of washer that is coated with a black oxide finish for added protection against corrosion and wear. Schnorr safety washers are designed to provide a secure and reliable locking mechanism for fasteners, preventing them from loosening or coming undone due to vibration or other external forces. The black oxide coating not only enhances the appearance of the washer but also improves its resistance to rust and other forms of corrosion, making it suitable for use in outdoor or harsh environments. These washers are commonly used in automotive, construction, and industrial applications where high levels of security and durability are required.