Choosing the Best Bolt According to Frederick E. Graves of The Scientific American, a refrigerator has 275 bolts, a fork-lift has 940, a car has 3,500, and a jet plane has 1.5 million. Essentially, the world is held together with bolts. But what is a bolt? Graves says it’s a “cylindrical, externally threaded fastener with a head.” Unlike a screw, though, a bolt is meant to be used with a nut rather than in tapped […]