| How’s it done? | Hounsfield tensometer | Instron tensometer | Universal testing machine |  

Tensile testing

How is tensile testing done?

Tensile tests can be conducted on a wide variety of tensile testing machines.

Below are photos of three different tensile testing machines.

Photo of a Hounsfield tensometer

Hounsfield tensometer.

Photo of an Instron tensometer

Instron tensometer.

Photo of a Universal testing machine

Universal testing machine.

The capacity of these machines can range from a few kilonewtons (kN) force to 100 000kN (the world’s largest test machine). The machine used to test steel for the Sydney Harbour Bridge had a capacity of 1270 kN.

A prepared specimen, usually of standardised size, is held in a gripping device and a gradually increasing axial load is applied. The load is usually applied until failure occurs.

The applied load (kN) is plotted against extension (mm), to produce a load/extension graph. Below are three examples of load/extension graphs produced by different materials.

A black mild steel load/extension graph

Take a closer look at a black mild steel load/extension graph (.pdf 160kB).

A bright mild steel load/extension graph

Take a closer look at a bright mild steel load/extension graph (.pdf 160kB).

A cast iron load/extension graph

Take a closer look at a cast iron load/extension graph (.pdf 160kB).

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What other materials testing equipment is used in industry?

Visit the websites of some testing equipment makers and create a mini catalogue of the key types of testing machines.

Be sure to include an image of the machine and a description of what tests the machine can perform.

Use the top navigation menu or ‘next’ button in the bottom right corner to have a look at each of these tensile testing machines in more detail.