One Company's Story: In-House Heat Treating a Success
The Fastenal Company, started in 1967, is an American company headquartered in Winona, Minn. Its primary business model revolves around the distribution of industrial supplies such as fasteners, industrial tools, safety equipment, electrical and plumbing supplies and much more. With over 2,600 stores located in all 50 states, Canada, Mexico, Central and South America and additional store locations in Europe and Asia, Fastenal is a very well-known name in the industry.
In addition to its distribution business, Fastenal also has facilities strategically located around the globe that manufacture everything from complex machined parts to high-volume production fasteners, including large-diameter bolts, nuts and complete stud assemblies as well as custom parts.
Fastenal serves a diverse customer base, including power generation, oil and gas, food and beverage, and equipment manufacturers. Its manufacturing capability includes hot forging, cold forming and precision machining. The manufacturing facilities complement Fastenal’s primary business model by “Making the unavailable part available.”
“We deal with a lot of competiveness in the marketplace,” said Cory Jansen, executive vice president of operations. “The company constantly looks at how it can stay ahead of its competitors.”
In the past two years, Fastenal has invested more than $7 million to bring secondary processes in-house. “Just having them in-house allows us to have quicker turnaround time and a better response to our customer’s needs,” Jansen said.
A portion of that investment ($2.5 million) went toward adding a heat-treat department into the 100,000-square-foot manufacturing building located in Winona. Prior to this installation, a majority of its heat-treat needs – approximately $1 million annually – were being serviced by commercial facilities in the Minneapolis-St. Paul area as well as a commercial plant located in the western Illinois area. This meant that one full day was devoted to delivery of the parts the 150+ miles to the Twin Cities or the Quad Cities areas, up to five days processing and another full day spent on the return trip.
The idea was to dovetail the heat-treat process directly into the Winona manufacturing facility to primarily shorten lead time. The expense of transportation and packaging was an additional cost that could be avoided as a result of having the capability to heat treat in-house.
In August 2013, Fastenal placed an order for its first piece of heat-treat equipment. The commitment was made.
Choosing the Equipment – Vacuum
“A number of furnace manufacturers were considered,” said Derek Foley, the manufacturing engineer placed in charge of the project. “For the vacuum furnace, we decided to go with Ipsen. Not only do they have an excellent reputation and a competitive price, but they could deliver a complete system much faster than any of the others that we considered.”
In December 2013, the vacuum furnace was delivered, and an Ipsen Titan Model 3100 24-inch x 28-inch x 48-inch (H4) 2-bar nitrogen-quench furnace was brought on line (Fig. 1) in February 2014. The primary mission of this piece of equipment and its companion Wisconsin Oven electric tempering furnace (of the same size) was to perform the hardening and tempering of the tooling that is used in the hot-forging and cold-forming operations.
The types of tool steels processed range from basic air-hardening types (e.g., A2 and D2 tools) to hot-work and high-speed tool steels.
“The ability to develop specific heat-treat cycles best suited to developing properties to the application that the tooling was designed for and having control over dimensional predictability after heat treat has been a real benefit,” said Earl Murty, the tool-room manufacturing manager.
Add that to the overnight turnaround and tools go from design and machining to production much faster than ever before. The vacuum furnace is also employed for such processes as carbide solution annealing of austenitic stainless steels, vacuum tempering of medium-carbon and medium-carbon-alloy steels, annealing, solution anneal and age hardening of precipitation stainless and nickel-based alloys, and the processing of many other materials that are used in fastener applications.
Choosing the Equipment – Atmosphere
In October 2014, Fastenal put into commission an AFC-Holcroft gas-fired E-Z Series modular endothermic gas generator and an AFC-Holcroft 36-inch x 48-inch x 36-inch universal batch quench (UBQ) furnace (Fig. 2). In addition to the UBQ furnace with top-cool capabilities, two companion gas-fired tempering furnaces, an aqueous wash system and a material-transfer system were installed to round out a complete normalizing and hardening, oil-quench processing line (Fig. 3).
“Not only is the AFC-Holcroft UBQ batch integral-quench system easy to operate and maintain, but the support that we continue to receive from AFC-Holcroft is outstanding,” Foley said.
The system’s primary design is to process medium-carbon and medium-carbon alloys. The capabilities of these two furnace lines allowed Fastenal to bring over 80% of its heat-treat processing needs in-house.
Choosing the Equipment – Controls
Both heat-treat systems – atmosphere and vacuum – have the latest process-management controls available. Both systems are calibrated to meet AMS 2750 Rev. E, instrumentation type D, furnace class 3 requirements with advertised temperature uniformity of +/-15°F (8°C). Through most of the temperature ranges used in the UBQ, vacuum and tempering furnaces, a temperature uniformity of +/-10°F (6°C) or better can be observed. Process recipes are preloaded for repeatability, and transfer time from austenitizing to quench in the UBQ is automatic, reducing process variability. The UBQ is equipped with a dual carbon-probe atmosphere-control system and a nitrogen atmosphere backup. In order to comply with some specifications, load thermocouples can be attached to the workpiece during processing.
Benefits of Captive Heat Treating
“From the very start of operations in this state-of-the-art heat-treat department, Fastenal has experienced turnaround of its heat-treat needs that can now be measured in hours instead of days,” said Joe Garteski, the Winona facility manufacturing operations manager. “In October 2015, the average turnaround was 2.2 days instead of the 7.5 days that we experienced when we were sending our heat treat to the outside. This makes a huge difference. If a customer has an emergency or is experiencing a line-down situation, we can respond much more quickly than ever before.”
In addition, there are many hidden benefits that Fastenal has experienced with bringing heat-treat operations in-house (Fig. 5). As previously stated, transportation handling/packaging, transportation costs and the ongoing problem of damage to threaded product is greatly reduced. The occurrence of damaged threads due to in-house handling is virtually nonexistent. Distortion of long, small-diameter bolting during heat treatment is reduced as a result of designing proper tooling and setup instructions to be used during thermal processing. As a result, time spent on secondary straightening/re-forming operations has been significantly reduced.
Of even greater value is the ability to acquire additional control over the heat-treatment quality of its products. Fastenal has an on-site A2LA-accredited testing laboratory that has the capability to perform tensile, proof-load and yield-strength testing of externally threaded fasteners; proof loading of internally threaded fasteners with loads up to 200,000 pounds of force; and impact testing, Skidmore-Wilhelm testing, corrosion testing and many other forms of destructive and nondestructive testing.
The ability to get feedback so that processes can be tuned is very valuable. The result is less time consumed by reworking product. Sure, there is an additional cost to having this type of processing in-house. But the Fastenal manufacturing team can and does offset the direct cost with the many “soft” benefits that come with developing this expertise in-house.
“Growth Thru Customer Service” is our goal, and Fastenal continues to invest in the future.