Some of engineering's mightiest achievements are small in scale, even hidden--and yet, without them, the complex machinery on which our modern world runs would not exist. In Nuts and Bolts, Roma Agrawal examines seven of these extraordinary elements: the nail, the wheel, the spring, the lens, the magnet, the string, and the pump.

From the physics behind both Roman nails and modern skyscrapers to rudimentary springs that inspired lithium batteries, Agrawal shows us how even the most sophisticated items are built on the foundations of these ancient and fundamental breakthroughs in engineering. Agrawal explores an array of intricate technologies--dishwashers, spacesuits, microscopes, suspension bridges, breast pumps--making surprising connections, explaining how they work, and using her own hand-drawn illustrations to clarify complex technical principles. Along the way, she recounts the stories of remarkable scientists and engineers from all over the world, and reveals how engineering has fundamentally changed the way we live.