Which Cut is Best, Water or Laser?

April 3, 2023

The short answer, according to a survey of major suppliers for each type of system, is waterjet is less expensive and far more versatile then laser in terms of materials it can cut. From foam to food, waterjets demonstrate an exceptional degree of flexibility. Lasers, on the other hand, offer unequaled speed and precision when producing high volumes of thinner metals up to 1″ (25.4-mm) thick.

In terms of operating costs, waterjet systems consume abrasive materials and require pump rebuilds. Fiber lasers cost more initially but are less costly to operate than their older CO2 cousins; they also might require more operator training (although contemporary control interfaces shorten the learning curve). By far the most common abrasive used with waterjet is garnet; in the very rare cases when something more abrasive like aluminum oxide is used, mixing tubes and nozzles suffer more wear. Using garnet, waterjet components might cut for 125 hours; they might only last roughly 30 hours with aluminum oxide.

Ultimately, both technologies should be seen as complementary, according to Dustin Diehl, laser division product manager for Amada America Inc., Buena Park, Calif.

“When a customer has both technologies, they have tremendous flexibility on what they can bid,” Diehl explained. “They can bid any type of work because they have these two different but similar tools and can bid the whole package.”

For instance, one Amada customer with both types of systems performs blanking on a laser. “Right beside the press brake is a waterjet that is cutting a heat-resistant insulating material,” Diehl said. “As soon as the sheet is bent, they put the insulation in, bend it again and execute a hem or seal. It’s a neat little assembly line.”

In other cases, Diehl continued, shops indicate they would like to acquire a laser cutting system but feel they aren’t taking in the volume of work to justify the expenditure. “If you’re going to make a hundred parts and it’s taking you all day to do it, we ask them to look at the laser. We can get a sheet metal application done in minutes, not hours.”

Having run a shop featuring about 14 lasers and one waterjet, Application Specialist Tim Holcomb of OMAX Corp. Kent, Wash. recalled a poster he saw years ago at company that used lasers, waterjet and wire EDM. The poster listed the materials and thicknesses each type of machine could handle best—with the list for waterjet dwarfing the others.

Ultimately, “I’ve seen lasers try to compete in the waterjet world, and vice-versa, and they’re not going to win outside their respective niches,” Holcomb explained. He also noted that, because waterjet is a cold cutting system, “We can tap into more medical or defense applications because we have no heat-affected zone (HAZ)—we are microjet technology.” Minijet nozzles and microjet cutting “are really taking off for us.