Superior Rock Bit: Custom design for Range mining

Drill bit legs after heat treating (right) followed by machining (left).


Tucked away in Virginia is a 12-person shop that quietly supplies most of the rock bits mining companies on the Range use to drill blast holes in iron ore.  

It’s Superior Rock Bit Company, a third generation shop whose founder, Frank Klima, developed a patented sealed bearing rock bit to fill the demand when bits were not available during the energy crisis of the mid 1970s.  Later, his son Dave took over management and four years ago his grandson Aaron became president.  

The rock bit is a product custom crafted from the spacing of the carbide teeth (which actually do the cutting) to the alloys used and bearing design.  Set on the end of a rotary drill string, the drill cuts into the rock using 110,000 pounds of pressure.  But the efficiency of the drilling and durability of a drill can be impacted by just what unknown material lies in the path of the hole.  Quartz veins, for instance, can seriously shorten carbide life.  

 It’s here that the local company can make a difference, Aaron said. Bits are custom made for the type of hard rock on the Iron Range, but they can be quickly changed when unexpected rock types appear during the drill. Experienced technicians are close at hand to help assess issues, and the company also will train mining company employees on what bits can and can’t do.   

 “We’re not just selling you a bit, we come along as a partner,” he explained. 

Superior Rock Bit is one of only a handful of companies that make the big bits, which drill holes from 12.25 inches to 16 inches in diameter.  Their only U.S. competition is in Pennsylvania.  

Bits are made from domestic steel, forged in Milwaukee and delivered as blanks to the shop in Virginia. There they are machined within tolerances usually at +/- 0.001 inch in a series of machines run by Class A machinists before being sent back to Wisconsin for heat treating. 

On their return, the parts go through more machining and are assembled with roller, ball and thrust bearings.  The carbides are hydraulically pressed into the cones and the three leg and cone assemblies welded together.  

The whole process takes about six weeks, with a batch of 24 bits completed about every week.  Production is as high as possible with one shift.  To add another shift would mean adding more machinists, and this, Aaron said, is difficult.

He sees a number of reasons for the lack of qualified machinists in the area - high schools that used to have machining equipment as part of shop now often don’t even offer shop classes. There are few local trade schools offering training - Lake Superior College being one.  The culture on the Range is not oriented toward equipment manufacturing, but rather toward fabricating, distributing and services.  Finally, the Range is not a preferred destination with the exception of young people who have grown up in the area. 

On the other hand, de said, people who have machining skills can make fantastic wages and 100 percent placement with a two-year academic investment.  And the Range, he said, is a great place to raise a family.

Aaron himself began at the factory at age 15, although, he pointed out, he had been mowing grass there since age 12.  Graduating from high school in Mt. Iron, he went to UMD for a degree in industrial engineering. 

At the shop, he uses that degree in making improvements to the product and production efficiency.  One exciting improvement is a new machine replacing one that is 22 years old.  Covering the first stage in leg production, the machine can hold 40 different machining bits and provide five axes of motion.  Changing bits takes just three seconds.  

Meeting his wife Amy through a mutual friend, the couple has two children, Madelyn, age 11, and Kyle, age 8.  Amy is a human resources specialist and also holds an MBA.  She manages the office, including accounting, marketing and human resources. 

The couple understands the economic variability of the industry.  A few years ago, the shop was idled every other week.  Now in full production, what do they expect in the future?

“As long as people understand where things come from, I think we’ll be OK,” said Aaron.  But the couple worries about the disconnect in modern society separating the product from the production, and the decline in hands-on experience for youth in a digital environment. 

“Behind every one of these products, someone has to make it,” said Amy.  

People who don’t want mining still want to go into an Apple store to buy an iPhone, they pointed out.  If minerals come out of northern Minnesota, they are mined under some of the strictest labor, environmental and safety laws in the country.  Minerals sourced in third world countries often don’t have those safeguards.  

“We can’t live on the Earth without using what the Earth provides,” Aaron said. “I say…use it in the best, most ethical and safest way that you can.”