JetTalk: Selecting the right edge quality for your project

From rough cut to precise edge quality finish.

One of the key requirements in abrasive waterjet cutting is to achieve a specific edge quality for your project.

The edge quality refers to how rough the edge of a cut part appears and how square or tapered it is. The edge qualities typically range from Quality 1 (Q1) to Quality 5 (Q5), with Q5 being the finest and most precise edge quality.

Waterjet Edge Quality 1Waterjet Edge Quality 2Waterjet Edge Quality 3Waterjet Edge Quality 4Waterjet Edge Quality 5
Q1 is described as a “separation cut”. While Q1 does not produce a high quality edge, it is created using very fast cutting speeds and can be used for roughing out parts. Evidently, it is a rough cut, and the edge has more pronounced lines, called striations or coining effect.
Q2 is a medium rough cut. The coining effects are less noticeable than a Q1 edge while the cutting speed is a little slower than Q1.

Q3 is a standard machining cut. It is the most commonly acceptable edge quality with scratches at the bottom half of the cut. However, more time is required to achieve this quality compared to Q2.

Q4 is a higher quality finish where the scratches are minimized.

Q5 is a very high quality finish with the most accurate edge quality. The cut is very precise with minimum taper.


Performance-wise, there is a correlation between the cutting speed and edge quality where the higher the quality of the cut, the slower the cutting speed. It is possible to choose Q5 for every job. However, you may find that it takes two or three times longer to achieve a Q5 compared to a Q3 on the same part.

As the time taken to cut parts is usually a major factor in the cost of a project, it is important that you select the right quality abrasive to achieve the best cut at maximum cutting speed for every job.

GMA ClassicCut™ 80 and GMA ClassicCut™ 120 garnet abrasives are known in the industry for their hardness, density and toughness with high purity and optimized particle size distribution.

In addition, using our garnet with the right combination of nozzles and orifices is highly recommended to achieve a better edge quality.
For nozzles, ROCTEC APX and ROCTEC 500 deliver better cutting edge for precision cutting applications in aviation, aerospace, automotive, defense, marble and stone (for artistic designs) and medical industries. These high-quality nozzles offer long, uninterrupted cuts or where close tolerances have to be maintained for long periods; to maintain parts integrity or to minimize expensive scrap from premature nozzle failure. As for orifices, diamond or tetraCore orifices produce a more cohesive stream compared to ruby or sapphire orifices.

With poor quality nozzles and orifices, you will find that the cutting speed reduces, precision cutting is diminished and the kerf widens. Moreover, the longer life nozzles and high-quality orifices help maintain longer jet pattern and velocity, resulting in faster cutting speed and the ability to perform longer uninterrupted cuts while delivering a better edge quality.

Like to know how to get the right edge quality at maximum cutting speed? Contact our technical teams today

By Hemanshu Dawda, GMA Middle East



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