Tough as Nails: The Tempering Process and Products You Use

We don’t often question if our drill bits are hard enough for the job or if our mattress springs are going to hold us up - we just expect them to work when we use them. But what makes a drill bit hard enough to drill through wood and other surfaces without breaking? The heat treating process known as tempering is one of the steps that makes this possible. 

What is Tempering?

In short, tempering is a heat treatment that increases the toughness of certain metals, namely iron-based alloys. The steel is heated to just under a specific temperature (known as the critical point) and then air cooled. The temperature at which an item gets tempered is based entirely on the application and desired outcome of the metal: drill bits would need to be tempered at a lower temperature than a mattress spring.

Tempering is but one heat treatment option when it comes to metals. Some other options would be annealing and normalizing. However, each process results in different outcomes. Tempering is best applied to products that are put under great stress, not only drill bits and springs (mentioned above) but also knives, bolts, nuts, screws, washers, and many more common products.

However, before tempering even happens, the steel has already gone through another heat treatment known as hardening. The hardening-tempering process happens in four steps. First, the steel is heated above the critical point. Then the steel is quenched in water or oil. This hardens the steel, but also makes it extremely brittle. This is where tempering comes in. The steel is then tempered and, lastly, re-quenched by cooling in air. The tempering process, followed by cooling, transforms the steel metallurgically and reduces the hardness to the desired level, resulting in a very strong, tough material with the right amount of hardness.

The Benefits of the Tempering Process

Tempering heat treatment is a necessary process in the manufacturing of steel products. The benefits of tempering are significant to improving not only the usability of the product but also its longevity.

The Benefits of Tempering on Metal:

• Structural stability
• Machinability
• Ductility
• Toughness
• Lifespan
• Weldability

Wisconsin Oven is a leading manufacturer of industrial heat treat ovens and tempering furnaces . Available in ten standard and custom sizes, Wisconsin Oven has a tempering furnace to meet your specific process needs. For more information about ovens from Wisconsin Oven, visit our website or contact us at (262) 642-3938. To stay up to date with company and industry information, visit our company pages on Facebook, Twitter, and LinkedIn.