$$\begin{array}{ccccc} \scriptsize \textsf{Nominal} & \textsf{Inside} & \quad\qquad\qquad & \textsf{Nominal} & \textsf{Inside} \\ \textsf{Size} & \textsf{Diameter} & \quad\qquad\qquad & \textsf{Size} & \textsf{Diameter} \\ \textsf{(in)} & \textsf{(mm)} & \quad\qquad\qquad & \textsf{(in)} & \textsf{(mm)} \\[0.5cm] \frac18 & 6.8 & & 4 & 102.3 \\[0.25cm] \frac14 & 9.2 & & 5 & 128.2 \\[0.25cm] \frac38 & 12.5 & & 6 & 154.1 \\[0.25cm] \frac12 & 15.8 & & 8 & 202.7 \\[0.25cm] \frac34 & 20.9 & & 10 & 254.5 \\[0.25cm] 1 & 26.6 & & 12 & 303.2 \\[0.25cm] 1\frac14 & 35.1 & & 14 & 333.4 \\[0.25cm] 1\frac12 & 40.9 & & 16 & 381.0 \\[0.25cm] 2 & 52.5 & & 18 & 428.7 \\[0.25cm] 2\frac12 & 62.7 & & 20 & 477.9 \\[0.25cm] 3 & 77.9 & & 24 & 574.7 \\[0.25cm] 3\frac12 & 90.1 \ \end{array}$$