It’s an age-old question that manufacturing engineers hotly debate in machine shops across the globe.
But SendCutSend answers the question with:
“Why not both?”
In addition to our state-of-the-art laser cutting, we utilize waterjet cutting to ensure that all your parts are cut to perfection at the best price. Additionally SendCutSend offers CNC routing, which is compared at a top level in our article “How We Choose the Perfect Cut for Your Part”. Often, the material and/or material thickness will drive the decision between waterjet and laser cutting. Ultimately, we strive to provide the highest precision parts for the best value in order to ensure our customers’ needs are met. This article will take a deep dive into comparing both waterjet and laser cutters, some advantages unique to each of them, the basics of how each process works, as well as when one is required over another.
Waterjet vs. Laser Cutting: What is the Difference?
Waterjet and laser cutting accomplish largely the same results, but in dramatically different ways.
Waterjet cutting utilizes the power of high pressure water to erode away material. This process is analogous to how the Grand Canyon was formed, though on a smaller scale in both size and time. The water (sometimes with additives such as sand, aluminum oxide, or garnet) slowly cuts away the material in its path by simple erosion. This process is fairly quick, at 1-20 inches/minute.
While waterjet relies on the power of water, the laser cutting process utilizes the power of FIRE! Well, technically the power of super concentrated light that heats up the material, but fire sounds cooler! A very fine laser heats up the material to the point that it either melts away, or vaporizes. Vaporizing is essentially going straight from a solid to a gas, skipping over the liquid phase.
For the adventurous DIY-er, laser cutting can be done at home with the proper equipment. We outline here Should You DIY or Rely on a Third Party for Laser Cutting. Laser cutting is typically very fast, operating at cutting speeds of 20-70 inches/minute which is up to 70x faster than waterjet. We discuss additional laser cutting capabilities in this post. Something else to consider with laser cutting is the heat affected zone. When the laser melts through the material, any heat treatments or temper to the metal will be lost in an area around that cut. Aluminum and high strength steels for example get much weaker in the area around a laser cut. Below is a table outlining the key benefits of each process.
|Thick Materials (>1”)||Thin Materials (<½”)|
|Fast (1-20 ipm)||Very Fast (20-70 ipm)|
|More environmentally friendly||Cheaper equipment|
|Less post-processing/finishing||More precise|
|Can cut more variety of materials||Quieter process|
Waterjet and Laser Cutting Precision and Speed
You’ve heard the adage: “Quality, speed, price. Pick two.”
You can have all three with laser and waterjet cut parts from SendCutSend. We provide quality parts, quickly, and at low costs. No compromises! These are all achieved with both the waterjet and laser cutter, but let’s go over the few differences in the processes that will affect how we choose which one to use for your project.
Production speed and precision for either waterjet or laser cutting depends on a few factors:
- Material thickness
- Thickness is a key consideration. If it is too thick, laser cutting is simply not an option as the heat build-up results in melted material on the edges. For waterjet cutting, thickness is less of an issue, and it can cut through very thick materials. However, with the increase in thickness comes a reduced speed as the water and/or abrasives still have to erode away the material.
- Laser cutting is more beneficial for thin sheet metal
- Waterjet cutting is more beneficial for thicker plate materials
- Here’s a chart of our material minimum and maximum sizes
- Type of material
- Material selection is also crucial in determining the speed and price of a cut. Consider cutting through a frozen cut of meat vs a thawed piece of meat. The frozen meat is much harder, and takes longer to cut through. Similarly, a piece of hardened steel like AR500 takes longer to cut through than a much softer piece of 6061 aluminum. This relationship in material hardness/durability holds true for both laser and waterjet cutting, the harder the material, the longer it takes to cut.
- Check out our material selection guide
- Intricacy of design
- Consider the two examples shown below. One has an intricate internal design, whereas the other is a simple outline and bolt holes. Much like any manufacturing process, the more details that have to be captured, the longer the manufacturing process takes. A key factor in the cost of manufacturing at SendCutSend (and everywhere else) is how long it takes to cut out. To put it simply, a simpler design will be cheaper, a more intricate one will be more expensive.
- Here’s a guide to understanding small geometry in laser cutting
Let’s unpack how all of those affect the production of your laser or waterjet cut parts.
Waterjet vs. Laser Cutting: Speed
Accurate estimates of speed will rely heavily on the intricacy of your design: the more intricate the design, the higher the cost. So if you want to cut a simple shape out of steel, like a 1/2” thick stainless steel plate with a hole in each corner, waterjet is a precise and cost-effective method to produce that part. But suppose you wanted to create a piece of artwork, such as a dragonfly wing? Your cost will increase proportionately to the intricacy of the design.
Laser cutting is a swift manufacturing process. Modern high-power (>4kW) fiber lasers can cut up to 80-100 times faster than waterjet in thin materials. Because lasers cut so quickly, they benefit from better machine utilization, thus lowering the cost of parts cut with laser.
Waterjet vs. Laser Cutting: Precision and Kerf
Waterjet cutting is a relatively high precision process, but you’ll need to prepare for a bit of tolerance. Tolerance is the difference between the specified dimensions and the finished dimensions of a part. For example, if you want one of your parts cut to a 10.000” length, and there’s a cutting tolerance of +/- .008”, your cut is within acceptable tolerance if it is between 10.008”- 9.992” long. Of course, we’re talking about eight-thousandths of an inch, but it’s still something we take into consideration when cutting your parts.
Cutting tolerance with a laser cutter is usually +/- 0.005”, or better. The diameter for a standard laser cutting beam is around 0.007” (which is about the diameter of a single strand of human hair.) Thanks to the small beam diameter, the kerf* is drastically reduced and precision increases with laser cutting. If we apply laser cutting to our dragonfly wing example, we experience virtually no issues with intricacy or detail, provided that we have appropriately designed geometry following our laser cutting guidelines. However, as material thickness increases, more heat is introduced to the material being laser cut. This additional heat can cause excessive slag (dross) or distortion.
*Kerf is a small amount of material beyond the diameter of the laser or waterjet that is removed during the cutting process, we account for this in all of our processes to ensure tight tolerances.
The kerf of the stream of water plus the blended abrasive in a waterjet is usually equal to 0.020” to 0.040”, depending on the material processed. Returning to our earlier example about the dragonfly artwork, if we wanted to have an extremely detailed wing, we’d have to consider our design’s small holes and features. Due to the waterjet’s relatively large kerf when compared to laser, small patterns and tight inside radiuses can get lost during the cutting process. But because there is no additional heat introduced in waterjet cutting, thicker parts don’t experience the same issues with dross or heat distortion.
Waterjet vs. Laser Cutting: Materials
Because waterjet and laser cutting are such vastly different processes, the materials they each can cut are equally as different. This is also one of the biggest reasons why having both a waterjet and a laser is so valuable for a machine shop.
To begin with, waterjet cutting is ideal for thicker materials. For example, most steels are good candidates for waterjet, but steel thicker than 1” is the best fit since lasers can “run out of power” after about 0.750” of thickness. In general, waterjet cutting is better for many thicker materials than laser cutting, at the expense of speed. The broad range of thickness that is acceptable for the waterjet method is about 0.040”- 4”. Projects less than 4” in thickness are most common.
Other types of materials suited to waterjet cutting are:
- Thick Metals (greater than ½” thick) – brass, carbon steel, tool steel, aluminum, copper, titanium, and more
- Natural Materials- leather, stone, marble, granite, and more
- Composites- fiberglass, kevlar, carbon fiber, and more
- Rubbers and Plastics- foams, polycarbonate, and more
Where waterjet cutting is best suited for thick materials, laser cutting is its perfect complement for precisely cutting thinner materials. For example, laser cutting is not well-suited for materials like granite, which is thick and brittle, and tends to shatter when exposed to the heat of a laser beam. However, laser cutting is fantastic for materials that are less than ½” in thickness, and cannot be processed as quickly or efficiently with waterjet, such as:
- Metals less than 1/2” in thickness – brass, carbon steel, tool steel, aluminum, copper, stainless steel, steel alloys, titanium, and more
- Natural Materials- wood, paper, cardboard, cork, and more
- Rubbers and Plastics- acrylics, PET, Delrin, and more
All in all, using a waterjet and laser cutter side-by-side allows us to cut all your parts, regardless of thickness and material, to greater precision and at a fraction of the cost.
General Laser and Waterjet Cutting Service Costs
Regardless of the cutting process used for your parts, the key factors driving cost are:
- Time spent on the machine: a more intricate design and thicker material both contribute to the amount of total time spent on the machine
- Material prices (this includes raw material prices): an expensive metal like copper or titanium will undoubtedly cost more than aluminum, and these prices often fluctuate
- Quantity of order: the more you order, the lower the unit price, thereby making it worth your while to make a few large orders as opposed to many small orders
- Automation factors reduce the cost of fabrication by reducing the personnel involved in physical work
SendCutSend is committed to making it as easy and affordable as possible for you to get custom parts, fast. The waterjet paired with the laser allows us to maximize parts being produced at a time, the kind of parts we can cut, and the kind of materials we can cut. All this contributes to a low cost for you and a faster production time. And who doesn’t love getting their parts more affordable and faster?!
The Machining Match Made In Heaven
Waterjet and laser cutting make the perfect machining pair. They play to each other’s strengths and bring unique benefits to the table, so it’s a machine shop’s dream to have access to both. And let it be said that SendCutSend does make dreams come true! We are proud to be offering waterjet cutting services alongside our state of the art laser cutting services. If you have any questions, feel free to reach out to us at email@example.com. When you’re ready, upload your design and get an instant quote today!
If you are new to SendCutSend, here’s a handy step-by-step guide on how to order parts from us: How to Order Parts from SendCutSend (spoiler alert: it’s super simple and intuitive to order from us).