2.375
The nominal bore of a pipe is its internal diameter. The nominal bore determines how much volume you have in the pipe to transport your particular substance.
The conversion factor to convert inches to "Nominal Bore" (NB) is 25.4 mm per inch. NB sizes are based on the internal diameter of a pipe, and they do not directly correlate to inches.
NB = Nominal Bore
Diameter drill is drilling.
bore of the pipe is the internal diameter of pipe but the nominal diameter of pipe is the dia of a circle which is draw through a point which is situates at exactly half of the thickness of pipe or we can say that (outer dia of pipe- thickness of pipe )=nominal bore of pipe.
NB (nominal bore) is the European designation equivalent to NPS is DN (diamètre nominal/nominal diameter/Durchmesser nach Norm), in which sizes are measured in millimeters. NB (nominal bore) is also frequently used interchangeably with NPS.You can refer more details herehttp://www.piping-engineering.com/nominal-pipe-size-nps-nominal-bore-nb-outside-diameter-od.html
Pipe bore is the actual minimum inside diameter of a pipe, which is not necessarily the nominal pipe size.
It means 20mm Nominal Bore or 20mm inside diameter piping.
NB stands for "Nominal Bore" and refers to the nominal size of the valve in a piping system, typically measured in inches. It represents the internal diameter of the valve or pipe. It is an important parameter used to select the right valve for a specific application.
NB = Nominal Bore. Bore is the internal diameter of the pipe. The 50 is referring to 50mm (5cm). So it boils down to a pipe with an internal diameter of 50mm.
the inner diameter of the pipe Nominal bore (NB) is 40 mm
Pipe with a Nominal Bore of 4 inch (100mm) Outside Diameter 114.3mm