Science
What is Wheel and Axle?
A wheel and axle is a simple machine made of a large wheel attached to a smaller rod (the axle) that turn together. Applying a small force to the rim of the big wheel produces a much larger turning force at the axle — or lets the axle move things a long way with each turn.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains wheel and axle.
Key things to understand
- 1The wheel and axle are fixed together and rotate as one unit.
- 2A small force on the large wheel creates a bigger force at the smaller axle (more turning power).
- 3Used the other way, turning the axle moves the wheel's rim a long distance quickly.
- 4Doorknobs, steering wheels, screwdrivers, and bicycle wheels all use this machine.
- 5The bigger the wheel compared with the axle, the greater the mechanical advantage.
Frequently asked questions
- How does a wheel and axle work?
- The wheel and axle are joined and spin together. A small force applied around the large wheel turns into a much greater force at the smaller axle — or lets the rim travel far with each turn.
- Is a wheel and axle the same as a wheel?
- Not quite. A simple rolling wheel reduces friction; a wheel and axle is a machine where the two are fixed together, so turning one turns the other, multiplying force or distance.
- What are examples of a wheel and axle?
- Doorknobs, steering wheels, screwdrivers, ferris wheels, bicycle wheels, and the gears inside many machines.