## Elementary Technical Mathematics

$\frac{5}{16}$ in
Lets consider the formiula for tap drill size , TDS = OD – P, where OD is the outside diameter and P is the pitch Given outside diameter is $\frac{3}{8}$ in and pitch = $\frac{1}{16}$ in So TDS = $\frac{3}{8}$ - $\frac{1}{16}$ =$\frac{3}{8}\times$ $\frac{2}{2}$ - $\frac{1}{16}$ =$\frac{6}{16}$ - $\frac{1}{16}$ = $\frac{5}{16}$ in