The NN-21-BK is a black nylon locking nut designed for secure fastening of fittings and pipes with a 3/4" NPT size. Crafted from durable nylon material, this nut offers exceptional resistance to corrosion, chemicals, and high temperatures. With its locking feature, it ensures a tight and reliable connection, preventing loosening and leaks. This versatile nut is ideal for various applications in industries such as plumbing, automotive, and industrial manufacturing. Count on the NN-21-BK for its excellent quality, ease of use, and long-lasting performance.