Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Cantilever Applications
Name: Teresa
Status: Educator
Grade: K-3
Location: GA
Country: United States
Date: May 2006

What is a cantilever used for?

Hi, Teresa.

A cantilever refers to an arrangement where something is supported rigidly at one end only.

This arrangement is not very structurally efficient, as the supporting end has to be rather bulky to provide the rigidity of support that is typically needed. That is, it has to be very stiff, and pretty much the only way to do that is to have more mass or heavier duty structure.

On the other hand, if a cantilever can be used, it permits a lot more design freedom, both for practical and decorative use. For example, a deck cantilevered off of the side of a house does not have any supports underneath, opening up the space for other uses. An equipment support that is cantilevered off of a mounting surface has open space at one end to allow for easier maintenance of the equipment.

So that is basically what it is. To see an example of how cantilevers are used in architecture, research the design of Frank Lloyd Wright's "fallingwater" on the web. They just finished a restoration project to keep the large cantilevered room from collapsing. It required massive anchors and lots of steel cables at the base, resulting in preservation of the free and open design.

David Brandt, P.E.

A beam is an element supported at both ends, in a bigger picture, a bridge is an element that spans a distance, supports a weight, and is supported at both ends. When a case arises, say a balcony where the element, or beam is logically supported from one end, that element is a cantilever. The loading and the stresses induced in the supporting element are analyzed. The procedures are the same for a cantilever, however there is more concern for the support, or connection. A post, or pole is a cantilever. The loading may be horizontal as opposed to vertical, for the balcony etc.

James Przewoznik

Dear Teresa,

A cantilever is a projecting beam supported at only one end. It can be used to make a bridge where at each end a cantilever beam projects toward the middle. They can then be joined directly or by a third beam to form the bridge. A shelf bracket is also a cantilever with the supporting member fastened to the wall and projecting underneath the shelf. I am sure you can think of many other uses for this design.

Best, Dick Plano, Professor of Physics emeritus, Rutgers University

Click here to return to the Engineering Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory