Service Heat Treating offers important process to metal makers

The company, located at 9320 N. 107th St. in Milwaukee, doesn’t actually make a product of its own but provides a necessary service for many area manufacturers. Service Heat Treating hardens or softens metal products manufactured by other companies through heat treating, or changing the mechanical properties.

“Nothing in this world would work without heat treating, but nobody knows it,” Armitage said.

Most of the time, the company hardens tool and stainless steel to give it additional strength. Vacuum, batch or tempering furnaces are used, depending on the application.

“We cook it just like you bake cookies,” Armitage said.

There’s a recipe developed for each product, so it can be cooked and hardened without changing its color or appearance. The company can work with all grades of metal in its 48,000-square-foot facility, he said.

The vacuum furnace removes all oxygen before the baking process so oxidation doesn’t change the color of the metal.

Elsewhere, employees feed trays full of parts into a 6,000-gallon oil batch furnace. A large flame burns at the front of the continuously running machine. After undergoing a batch treatment, parts are quenched in a vat of oil.

After batch treatment, if a metal is overly hard, a tempering furnace is used to draw back the level of hardness.

Sometimes, a customer would like steel products softened through annealing, usually so an extreme bend can be made in the metal. The process is similar to hardening, where parts are cooked in the vacuum or batch furnaces, but the cooling time makes the difference.

Softening is achieved by slow cooling the part over several hours, while hardening takes just minutes after the part is dipped in oil.

About 80 percent of parts that come through Service Heat Treating are treated in its four batch furnaces, while 20 percent are baked in its two vacuum furnaces.

For some types of equipment, carbon is added to the surface of the metal through carburizing, which makes the outside of the part harder than the inside. This assures the product is not too hard all the way through, causing brittleness, but is still able to withstand significant stress from applications such as mining or construction work.

If a customer isn’t sure which heat treatment is needed for its parts, Service Heat Treating can help them engineer a solution, Armitage said.

The company was established in 1974 by Paul Armitage’s father, Richard. He had been selling furnaces to heat treating companies, and saw that the companies were not treating their customers very well, Paul Armitage said.

For that reason, Richard Armitage founded Service Heat Treating with a focus on good customer service.

Paul Armitage bought the company from an owner partnership in February. The company has 28 employees, who treat products for about 400 metal companies within a 100-mile radius. The employees work four shifts, seven days per week, since it takes eight to 12 hours to shut down a batch furnace.

Service Heat Treating has about $4 million in annual revenue. It had to sell off several small divisions, like coating and grinding plants, to keep afloat during the Great Recession. It also reduced staffing levels from 100 to 28.

“When most people went down 30 or 40 percent, we went down 70 percent,” Armitage said. “I lost my top five customers.”

Three of those customers closed their doors, and one moved to Mexico, he said. Trimming other divisions helped Service Heat Treating get back to its core competency and main business driver, heat treating.

Now, Armitage is working to expand the company’s customer base and explore other heat treating processes that it could make available.