Marketing InformationPVC/CPVC/PE nipples furnished may be produced from extruded stock or from molding-grade PVC/CPVC compounds. Both processes provide quality products meeting ASTM requirements. Spears® thermoplastic nipples are produced in a variety of styles, several of which are illustrated below. These are referred to as plain (no threads), TOE (threaded one end), TBE (threaded both ends), grooved (which can be plain x groove, groove x thread and groove x groove). Special varieties of polyethylene nipples include cut-off, 4-in-1 cut-off and 4-in-1 cut-off reducing.