Maintain the Flame

Hot and getting hotter: New oxyfuel cutting capabilities help this metal service center grow its business in the highly competitive value-added metals processing sector.

Reliance Steel & Aluminum Co. (Los Angeles, CA) is one of the largest metals service center companies in the U.S. The company prides itself on the ability to supply quick turnaround and value-added metals processing capabilities to its more than 95,000 customers in a broad range of industries.

With a network of more than 180 locations in 37 states, as well as in Belgium, Canada, China and South Korea, Reliance Steel also distributes a full line of more than 100,000 metal products, including galvanized, hot-rolled and cold-finished steel; stainless steel; aluminum; brass; copper; titanium and alloy steel.

The company's National City, California, division focuses largely on structural steels and plate cutting of carbon steel, aluminum and stainless steel. The primary industries they serve include the shipyard industry, construction and bellows manufacturing.

Ken Goswick has worked for the company for more than 20 years and has seen the growth and change in cutting machine technology up close: "When I first started here in the late 1970s, the machines were all tracing machines. The industry was just getting into computerized machines. You still had to punch in the programs by hand. You had to draw large drawings to scale for the tracers to trace."

Goswick is now Reliance Steel's sales manager, but he is still actively involved in the day-to-day operation of the plant, especially the CAD programming. He has come to appreciate what today's cutting technology has to offer for a company that prides itself on turnaround and the ability to provide accurate shape cutting for its customers.

"In 2006, we replaced one of our older machines with a new ESAB Avenger 1 oxyfuel cutting machine," says Goswick. "This machine is one of the most accurate flame cutting machines I've ever seen."

The Avenger 1 is a large gantry cutting machine designed for oxyfuel and plasma cutting and beveling, marking, drilling and routing. The machine can be configured with up to 12 stations over cutting widths ranging from 8 to 20 ft. Reliance Steel's Avenger is equipped with four oxyfuel stations. The machine is designed with the option to add plasma cutting capability at a future date. Reliance currently has another dedicated plasma cutting machine that sufficiently handles their current plasma business, but they may add the plasma capability to the Avenger if their plasma cutting business continues to grow.

The gantry design features all welded, stress relieved, reinforced components with all contact surfaces machined to ensure accurate match up with mating surfaces. Machined wheels and roller bearings provide smooth, precise machine motion. A thick-wall box beam provides ample strength and stiffness to support up to twelve process stations. An independent reinforced deck supports all auxiliary equipment without placing any additional torsional forces on the main beam.

The main rail system is a floor-mounted assembly with machined "T" rails mounted on steel pads. The "T" rails are machined on three sides with a machined tongue-and-groove on the ends to interlock at joints, thereby eliminating sideways movement. Drive racks are mounted directly to the machined surface of the rail, ensuring proper alignment.

Process equipment is mounted on carriages that travel across the main beam with precise accuracy provided by machined ways and roller bearings. The upper drive carriage is connected to a stainless steel band to which additional carriages can be clamped for similar or mirror image paths.

Cut quality and accuracy are dependent on smooth, precise motion control in both axes. This gantry cutting machine accomplishes this by matching digital drive amplifiers and AC brushless motors with precision gear boxes and rack-and-pinion gearing. Racks are mounted away from the cutting process to prevent contamination from dust and debris. Travel speed can be varied from 2 to 750 ipm (50.8 to 19,050 mm/min).

Although oxyfuel cutting is not often associated with cutting intricate parts, the accuracy of this machine, combined with the skill of Reliance Steel's operators, allows the company to cut some fairly intricate pieces in carbon steel plate up to 6 in thick. One part cut for a bellows manufacturer consists of a 30 in outer diameter circle with cut-outs like the spokes of a wheel. The cross-sections are 1 in wide. "We've had people think these parts were plasma cut because they are so straight and narrow," remarks Goswick.

The accuracy and ease of programming is also handy for the company because they have many small runs that require changes in set up. The gantry cutting machine's size and accuracy allows them to nest multiple jobs on a plate with minimal interference.

Another key advantage of this machine's technology is its reliability and the ability to pick up a cut at the exact point where it was lost if, for example, they experience a power loss. "This is a big thing for us," states Goswick. "We use plate that costs $5000 apiece. If you lose the cut, you can ruin the plate. With the Avenger, if you lose power or lose the cut, the machine will return to exactly where you left off."

Reliability is critical because of the potential loss in business if a machine goes down. The Avenger, for example, runs continuously all day, sometimes two shifts a day. "We lose thousands of dollars if a machine goes down," explains Goswick. Since the company installed the Avenger 1 in May 2006, they have not experienced a single problem with the machine. The equipment includes a link to the ESAB factory through a diagnostic telephone line that ESAB can use to update or correct any problems with the CNC without needing to send out a repair person.
One of the main reasons Reliance Steel chose to purchase this equipment was because they had two older ESAB machines that ran reliably for years. The new machine is following in the footsteps of its predecessors.

Reliance Steel & Aluminum Company, 350 South Grand Avenue, Suite 5100, Los Angeles, CA 90071, 213 -687-7700; Fax 213-687-8792, www.rsac.com.

ESAB (U.S.) Cutting Systems, P.O. Box 100545, 411 South Ebenezer Road, Florence, SC 29501-0545, 843-664-4394, Fax: 843-664-4403, www.esabna.com.