Story and photography by Capt. Vince Daniello

My kit centers on one set of wrenches (some metric and some SAE) that covers both systems with no overlap. A 7/8-inch wrench is tight enough to turn any 22-mm bolt unless it’s completely seized (although a 22-mm wrench is too small to fit on a 7/8-inch bolt) so my 7/8-inch wrench does double duty. A 19-mm and a -inch wrench are interchangeable, but a 9/16-incher has no metric equivalent. A few wrench sizes are commonly needed in pairs. And 12-point combination wrenches swing in tighter spaces than six-point wrenches.I also pack 10-inch (extra-wide opening) and 6-inch adjustable wrenches with rubber handles for working on battery terminals.