WIDEMNET USED: These thin hex nuts are widely used for plumbing on pipe and thread pipe, meet your needs in different places. STRONG AND DURABLE: Made of high quality brass , which ensures these lock nuts are sturdy and durable SIX SIZES: There are six sizes of lock nuts in this set that can meet your needs. COST -EFFICIENT: One order, you will get these nuts 40 pieces, can be used in many places. HEXAGONAL DESIGN: These nuts are hexagon design, good slip resistance, more practical.