Threaded Flange, Flat Face, 1 in Nominal Pipe Size, Flanged x FNPT, 4 1/4 in Flange Outside Diameter, 9/16 in Flange Thickness, 4 1/4 in Overall Length, Aluminum, Class Class 125, For Pipe Schedule 40, 125 psi Maximum Operating Pressure, 185 psi Max. Steam Pressure, 0 Degrees to 270 Degrees F, Number of Bolt Holes 4, 1/2 in Bolt Hole Diameter