Chapter 45, Problem 49A

The solution of the following problems requires more than one formula and the rearrangement of formulas.

Use $C=\frac{3.1416DN}{12}$ or $\frac{\pi DN}{12}$ for customary units and
$C=\frac{3.1416DN}{1000}$ or $\frac{\pi DN}{1000}$ for metric units.

$N=\frac{12C}{3.1416D}$ or $\frac{12C}{\pi D}$ for customary units and
$N=\frac{1000C}{3.1416D}$ or $\frac{1000C}{\pi D}$ for metric units.

   $T=\frac{L}{FN}$

Aluminum baseplates are produced that are $1\frac{5}{8}$ inches thick. Six $\frac{1}{4}$ inch-diameterholes are drilled in each plate using a feed of 0.004 inch per revolution and a cutting speed of 300 feet per minute. Setup and handling time is estimated at 0.5 minute per piece. What is the total number of hours required to produce 850 aluminum baseplates? Round the answer to 1 decimal place.