McMaster 4627K335 Medium Pressure Iron Pipe Fitting, Plug with External Square Drive, 1 NPT G0329637 Emergency Response Guide Emergency Response Guide Diameter Tolerance Maximum 0 in Pressure Rating Medium Pressure Shape Cap and Plug Drive Style External Square Fitting Type Plug Fitting Connection NPT Male Pipe Size 1 Construction Solid Pressure Class 300 Body Shape Square Material Iron Maximum Pressure @ Temperature 400 psi @ 72° F Maximum Steam Pressure @ Temperature 300 psi @ 550° F Certification UL Listed Connects To Pipe Class 300 Material Steel For Pipe Material Steel For Pipe Schedule 80 For Use With Air these can handle medium pressure applications