Waterjet Cutting for Metal: What to Know


Flow Mach 500

The Flow Waterjet has quickly propelled itself forward as one of the most undeniably powerful and versatile cutting machines on the market. Relied on by countless fabricators, Flow offers a machine tool that performs like no other in its category. However, with the ability of the machine comes many questions that manufacturers ask before adding this resource to their shop. Northeast Machinery Sales Flow Service Technician, Jesse Smith, and Flow Regional Applications Engineer, Eric Marciniak are experts on the waterjet. They answered some of the most pressing questions from those curious about the machine’s capabilities.

Jesse: How can customers determine if the Flow Waterjet is right for them?

“The Flow Waterjet provides one of the most reliable cuts out of any machine currently on the market. Flow’s accuracy is unparalleled, with each cut coming within 0.015” of the original design. Closer tolerances can be achieved when necessary, however this does require slowing the machine down which in turn impacts the cost and time per part.”

“Another unique feature of the Flow Waterjet is its ability to cut through virtually any material. Effectively, the water tank and slats catch the force of the stream, slowing the water and abrasive mixture down enough so that it does not cut through the base of the machine. Theoretically, if the water tank was not there, the Flow is powerful enough to eventually wear down and cut through the floor where it sits.”

“When it comes to choosing a cutting machine, it’s important for customers to think about what they’re using it for. The Flow Waterjet has been able to gain traction in a multitude of different industries for its ability to cut through virtually any material. While I mostly see the waterjet being used to cut metal, this machine can also cut through stone, tile, composites, ceramics and glass.”

Eric: What applications and materials should be considered best for a waterjet?

“Versatility is what makes waterjet unique compared to other technologies like plasma, router or laser. Virtually any materials and any thicknesses can be cut on a waterjet machine. Every other cutting technology option will have limitations on material type and thickness. Not Waterjet. Waterjets also offer a cold cutting process which means that there is no heat affected zone (HAZ). This makes secondary processing easier, or can even allow you to eliminate completely, saving time and money.”

Jesse: What are the top 3 things to consider when deciding to purchase a waterjet?

“The three main considerations of metal fabricators when deciding on a waterjet are material, psi and machine size. While some recommend using cutting machines such as lasers for thinner sheets of metal, the Flow Waterjet can cut through any thickness without hesitation. Material considerations also include what kind of material is being cut, however this will on play into the decision of a pure or an abrasive waterjet.”

“Another consideration is the psi, or pounds per square inch. The psi largely determines the speed of the cut, and for fabricators mass cutting parts, a higher psi will allow for a lower cost and time per part. Moreover, the psi will determine the operational costs of the machine as higher psi’s allow for less garnet to be used.”

“The Flow Waterjet comes in a variety of sizes, without compromising on power. Different machine sizes represent the number of parts being cut, as well as the space in a metal fab shop. However, even with the smallest Flow Waterjet on the market, the same cuts can be achieved as if they were cut on the largest waterjet.”

 Eric: How should power/speed be considered for a fabricator?

“The customer’s needs depend on their cutting application. There are only 2 ways to cut faster in waterjet. You can either increase horsepower (which requires an increase in water and abrasive which equates to an increase in operating cost), or you can go up in pressure. Moving from 60,000psi to 94,000psi generates a stream of water that is 500 mph faster … this faster thinner stream of water entrains less abrasive, so you actually cut faster while using less abrasive which is your biggest operating cost driver.”

One of the most impressive factors of Flow’s Waterjet are the servicing options. They range from completely DIY to options that ensure continuous preventative maintenance from a Flow certified technician.

Mid Atlantic Machinery is a certified Flow parts distributor. We maintain a consistent stock of all consumable parts. Cut shipping time and cost in half by ordering often replaced parts like nozzles, seal kids and blast shields from our showroom in Harrisburg, PA.  Mid Atlantic Machinery’s spare parts option offers an ease of mind when replacing consumables.

From ease of use to service to spare parts, the Flow Waterjets are a versatile machine tool fit for any fabrication shop. The waterjet is suitable for almost any cutting application- no matter the material. The power of Flow is unparalleled by any other waterjet on the market and could be the right machine for you.

For more information on the Flow Waterjets, waterjet cutting, spare parts or service please contact Mid Atlantic Machinery.