Waterjet Cut Quality is one of the most important choices that you can make in having a project cut. You basically have 5 choices but the average consumer may not even be aware of them. They are generally rated today on a scale of #1 to #5.
Everyone needs to understand how their waterjet supplier rates their waterjet cut quality, which is generally determined by the brand of machines that they use for the cutting process. Most companies use a rating system that uses #5 as the best available edge quality with #1 as the roughest cut or poorest quality.
Waterjet Cut Quality #1
#1 Edge
Most systems rate #1 as a “Separation Cut” which is a very rough cut that might be comparable to an RMS500 or rougher surface finish. It will be characterized by many very pronounced lines called striations running somewhat parallel to the stream cut along the edge of the material. You will often get the strange globs at the bottom of the cut due to the kick back of the stream as it is skipping when it is barely getting through the material. The thicker the material the more pronounced these will be. These striations can cause variations in dimensions that could be as much as 1/8″ in materials of 3″ thickness or more. Because of these issues we do not recommend using this waterjet cut quality at all.
Waterjet Cut Quality #3
#3 Edge
At Accurate Waterjet we will always use a #3 edge quality or better unless you specifically request something rougher. Many other waterjet cutting companies will use a #1 or #2 edge cut in order to cut the parts faster and thus make them cheaper, but may not always pass that savings along to you the customer and thus giving you a less than satisfactory part for a less than satisfactory price. In this competitive business companies often think that getting the job in the door is the #1 priority, then once they get the job they may cut corners to try to make the parts as cheaply as possible.
Waterjet Cut Quality #5
#5 Edge
A #5 cut will have none of the above mentioned striations at all and will have a minimal amount of roughness much closer to an RMS125 and can even approach an RMS60 finish in some cases. This can give you a finished part that will not require further machining at all in order to be usable as a completed part in many cases. As a reference it might take 11.5 minutes to cut a part with a #5 cut quality, but would only take 3.5 minutes at a #1 cut quality. The #3 would be in the middle at 6.5 minutes. Since cost has a direct relation to cutting time, and edge quality is driven by cutting speed, you can see that edge quality is a major driver in cost of cutting a project.
We will usually ask what the end product is to be used for in order to help you make an informed decision on edge quality. We want you to be an informed consumer, and feel that knowledge is power in your shopping experience.
When you come to Accurate Waterjet we will routinely ask you what waterjet cut quality you would like to have as it is important that every customer goes away feeling that they got what they expected at the very least if not more. BEWARE OF THE LOWEST BID, AS YOU NORMALLY GET WHAT YOU PAY FOR!
Holy cow, there are 5 choices when it comes to water cutting, I am really impressed. My uncle just bought a machine that cuts with water, but I had no clue that it could do all of these things. What are the main materials that they are used for?
Waterjet machines can cut virtually any material that you can put under the cutting head as long as it is not harder than the abrasive that you are using. You could even cut diamonds if you were to use a diamond abrasive, but that would not be practical. I have cut solid carbide with the waterjet before but you have to use silicon carbide abrasive and due to the fact that it is just as hard as the components that the cutting system is made from it will destroy the whole cutting head very quickly (like in a matter of minutes) so you had better have deep pockets and really want to cut the carbide in a big hurry to try it. I know of no other machine that will work on as many different materials as the waterjet machine will.
It was handy to know that cost has a direct relation to cutting time with a waterjet cutter. My son learned about this in school 2 weeks ago and wants to cut out a silhouette of a Pokemon. I would imagine this would be a great birthday present for him this March!