Our durable galvanized steel is hydrostatically tested and available in sizes to fit residential and light commercial water applications. The 1/4″ x 1/8″ galvanized reducing coupling is for use with residential potable drinking water applications. Galvanizing on fittings is done by hot dip process according to ASTM A153, and certified to NSF 61. Always check your local plumbing and gas codes before starting any piping projects.