4-1/2 National Standard Thread Brass CapThe 4 1 2 NST Brass Cap is a heavy duty cap designed to securely seal National Standard Thread hose fittings, standpipes, and hydrants. Built from solid brass, this cap provides excellent corrosion resistance, durability, and reliability in fire protection and industrial applications. Specification Value TYPE National Standard Thread Brass Cap DESIGN NST Thread Compatibility designed for fire hose and hydrant fittings MATERIAL Brass for excellent