Stone Equipment Presents Custom KOBELCO Machine

To meet the demanding production requirements of a large-scale site development project in eastern Alabama, AGX Siteworx of Opelika, Ala., has added a new KOBELCO SK520LC-11 excavator to its fleet. The machine was purchased from Stone Equipment Company.

The custom machine was presented to AGX at ConExpo-Con/AGG 2026 in Las Vegas, Nev., last month.

The 55-metric-ton production-class excavator is powered by a 463-hp Tier IV Final Isuzu 6WG1 engine and is paired with an AMI Attachments XMOR BHB 5.6-cu.-yd. bucket, a high-capacity configuration designed to efficiently move large volumes of material in mass excavation applications.

The SK520LC-11 is now working on a major site development project in the Opelika, Ala., area, where AGX Siteworx is responsible for large-scale earthmoving, grading and site preparation. The scope of work requires moving substantial quantities of material on a tight schedule, making high-production equipment critical to maintaining timelines and minimizing inefficiencies.

The AGX Siteworx team told Construction Equipment Guide the primary challenge on this job is simply the volume of material that has to be moved. Traditional mid-size excavators are not able to keep up with the pace required on a project of this scale.

Excavator Delivers Performance for Mass Excavation

Designed for demanding mass excavation, the SK520LC-11 delivers the power, hydraulic performance and fast cycle times needed for bulk dirt work and large site development. Its high-output engine and optimized hydraulic system provide strong breakout force while maintaining consistent performance during extended duty cycles.

When combined with the XMOR BHB 5.6-cu.-yd. bucket, the excavator is able to move more material per pass while maintaining stable operating characteristics and efficient machine balance.

Gains in Productivity, Fuel Efficiency

Since putting the machine to work, AGX Siteworx has realized measurable gains in productivity. The increased bucket capacity reduces the number of cycles and passes required to move material, lowering total machine hours and improving cycle times. In turn, this has helped reduce fuel consumption per yard moved while keeping the project on schedule.

"The SK520LC-11 has made a noticeable difference in our productivity," said Bo Holland, COO of AGX Siteworx. "Being able to move more material with each cycle has helped us stay ahead of schedule and operate more efficiently."

Longstanding Relationship Drives Decision

AGX Siteworx is a long-time KOBELCO customer and this purchase represents the contractor's sixth KOBELCO excavator. According to Holland, Stone Equipment and KOBELCO have consistently delivered reliable equipment supported by strong parts and service performance.

"Stone has been an outstanding partner every step of the way," Holland said. "Stone and KOBELCO have exceeded our expectations across every purchase and their parts and service support is second to none."

The sale was handled by Stone Equipment salesperson Jake Russell, who has worked with AGX Siteworx for more than eight years.

"I've worked with AGX for about eight years now, so it's more than just a business relationship at this point," said Russell. "I understand how they operate and what it takes for them to stay productive. A lot of times, I can see where they're headed and what they're going to need before they even have to ask."

Over that time, Russell has developed a detailed understanding of the contractor's production demands, equipment preferences and long-term fleet strategy.

"With the size and pace of their current work, it was clear they needed a true production machine, and the SK520LC-11 with the XMOR bucket was the right fit," Russell said.

Dealer Support, Warranty Back Investment

The excavator is backed by KOBELCO's standard warranty, which provides four years or 4,000 hours of coverage, supporting AGX Siteworx's long-term equipment investment.

AGX Siteworx is a full-service heavy civil contractor committed to delivering high-quality work while maintaining aggressive project schedules. With the addition of the KOBELCO SK520LC-11, the company is positioned to handle high-volume earthmoving demands efficiently and cost-effectively.

Stone Equipment Company, founded in 2010, serves customers throughout the Southeast with four locations in Alabama (Birmingham, Huntsville, Mobile and Montgomery) as well as Statesville, N.C., Richmond and Roanoke, Va., and a new facility coming soon to Atlanta, Ga.

Stone Equipment supplies equipment for construction, aggregate, demolition and environmental applications. Stone focuses on pairing contractors with equipment solutions that support productivity, efficiency and long-term success.

For more information, visit stoneequipmentco.com and agxsiteworx.com. CEG

This story also appears on Construction Equipment Guide.