If you are doing this exercise as a make-up or as homework, you can
do it without a box of actual bolts. Simply print out this page and
use the bolt picture instead! You can measure right off the picture.
The picture below shows all 15 bolts--you just won't have three or four
of each. The tops of some of the bolts are shown, and bolts that
have a terminal groove that might not be readily visible are marked with
an asterisk (*).
Back to the exercise!