Cast Iron per ASTM A126, Class B.
SEAT: Bronze per ASTM B584, CDA-836.
PLUG: Bronze per ASTM B584, CDA-836.
SPRING: Type 304 (18-8) Stainless Steel per ASTM A313.
BUSHING: Bronze per ASTM B584, CDA-932.
RETAINING SCREWS: Type 304 (18-8) Stainless Steel per
ASTM A276.