Bronze and Brass threaded fittings are manufactured from smooth-cored castings, designed to provide full flow with minimum restriction. All threads are accurately machined and gauged to ensure a perfect fit with the pipe. All fittings are individually tested under water to ensure quality. Note: the 1/8 inch and 1/4 inch size plugs are available in Brass only. NPT (tapered) threads should be sealed with PTFE plumbing tape or equivalent.