Standard Cut Groove for Specifications for IPS / BS / ISO / JIS Pipe Gasket Seating Surface (Column 3): The gasket seating surface shall be free from deep scores, marks, or ridges that could prevent a positive seal. Groove Width (Column 4): Groove width is to be measured between vertical flanks of the groove side walls. Groove Diameter (Column 5): The ‘C’ diameters are average values. The groove must be of uniform depth around the entire pipe circumference. Minimum Wall Thickness (Column 6): The ‘t’ is the minimum allowable wall thickness that may be roll-grooved. Groove Depth (Column 7): The ‘d’ is for reference use only. The groove dimension shall be determined by the groove diameter ‘C’. CUT GROOVE SPECIFICATIONS A O.D. B C d