What is what are jam nuts?

Jam nuts are a type of hardware fastener that are used to secure bolts, screws, and other threaded components in place. They are typically smaller and thinner than standard nuts and are designed to be threaded onto a bolt or stud after a larger, regular nut has been tightened. This second, or jam nut, is then tightened against the first nut to lock it in place and prevent it from loosening over time due to vibration or other forces. Jam nuts are commonly used in automotive, construction, and industrial applications, as well as in the assembly of machinery, equipment, and furniture. They are often made of steel, stainless steel, or brass, and may be coated or plated with a corrosion-resistant finish to improve their durability and longevity.