How do chocks and pitons work as climbing anchors?

In the context of mountaineering, both pitons and chocks serve as essential components of a climber's protection system, though they function through different mechanical principles.

A piton is a metal spike, wedge, or peg that is physically driven into a crack or fissure in a rock or ice surface using a hammer. It relies on the friction and mechanical interference created by being forced into a narrow space to provide a secure anchor point for the climber.1

Chocks, often referred to as nuts or passive protection, function differently. Instead of being driven into the rock, they are shaped metal wedges designed to be slotted into naturally occurring constrictions or tapering cracks. When a downward force is applied—such as during a fall—the chock wedges itself more firmly into the narrowing rock, creating a secure hold without damaging the surface.

While pitons were historically common, modern climbing ethics prioritize the use of removable protection like chocks to minimize permanent impact on the rock face, upholding the principle of preserving the natural environment for future generations.