Proven Solution: Grinding Concrete with RK4-01

A road construction company in the Pacific northwest was tasked with grinding a concrete surface as preparation for new asphalt paving. The requirement was to grind up to 3 inches deep and included the added challenge of having river rock mix. To grind the concrete, the company set out using an ASTEC Roadtec RX-600 Cold Planer equipped with Kennametal KPF303R toolholders spaced at 15 mm and a competitor road milling tooth. 

For a 500-foot-long stretch of road, the teeth on the left side of the RX-600’s drum were to cut  1 inch into the road surface and the teeth on the right side of the drum were to cut 2.5 inches into the surface. The road, however, was not that easy to mill. The cold planer’s teeth suffered extreme tip wear and tip loss, leading to frequent tool change-outs and low productivity.

The road construction company turned to Kennametal to see if we could solve the problem. We proposed a side-by-side product comparison on a second 500-foot-long highway run. 

The result?

The competitor milling teeth continued to have tip loss at a rate of 80 percent but Kennametal’s cutting tools did not lose any tips. Furthermore, the Kennametal teeth on average lasted twice as many feet as the competitor’s teeth.

By equipping its RX-600 exclusively with RK4-01 milling teeth, the road construction company experienced smoother cuts, lower fuel consumption, less time changing tools, reduced tooth costs, and overall greater productivity. 

A Texas road construction company was scarifying 1/8 inch of concrete across a two-mile-long, four-lane-wide city street. Dissatisfied by the lack of durability of a competitor’s cutting tools used with its cold planer, as well as the expense of frequently replacing them, the company scheduled an urgent product test with us to see if one of our Road King™ solutions could provide a better cost-to-performance ratio. 

Prior to our product test, a full drum of the competitor’s cutting tools were benchmarked as lasting one 1200-foot pass before reaching end of life. Their total surface scarification measured 8700 square feet. The construction company’s application engineer noted that these cutting tools wore down quickly on the carbide and the wear pattern deteriorated by the end of the first pass.

Next, the cold planer’s drum was outfitted with Kennametal concrete-specific RK3-PT cutting teeth. They lasted three separate 1200-foot passes on the same job before reaching end of life, and a total of 26,767 square feet of concrete was scarified. 

On a follow-up Kennametal test, the cold planer’s drum was outfitted with our RK4-01 cutting tools. They, too, lasted three separate 1200-foot passes and scarified a total of 26,767 square feet of concrete before reaching end of life. 

Both of our Road King solutions lasted three times as long as our competitor’s cutting tools, and their bodies showed consistently even wear. The sharper RK3-PT tools had a smoother initial set in. In comparison, the RK4-01 tools had a wear in phase, but once sharpened, the RK4-01 tools maintained a consistent and even wear pattern through end of life. The RK4-01 proved to be an effective concrete tooth without the extra cost a specialized design.  

The RK4-01 cutting tool is now used by the road construction company in its concrete scarifying jobs.

In 2023, Kennametal started the launch of the next generation of Road King cutting tools. The design elements maximize tool life and make change-outs of milling teeth easier. Features include:

• Superior performing teeth with improved body, washer, and retainer
• Body shape with wear indicators that enable machine operators to recognize new teeth
• Heavier body shape and washer that provide extra wear protection
• Retainer with double stop tabs that offers better consistency with rotation and retention

Explore the full line of Road King solutions.