Machining and fabricating industries use a lot of different cutting techniques among others, and one such technique is abrasive waterjet cutting. It is used for accelerated erosion of hard materials like metals.

The orifice of a water jet is the most important part of it, allowing water mixed with garnet sand to push through at high pressure without damages to the instrument. This orifice is jeweled, and often materials like ruby or sapphire is used to make a tiny nozzle through which the water is pushed through. Owing to the hardness of these materials, it becomes possible to push water at such high pressure, focus the water stream, and make smooth cuts.

So, here we are, with some information about sapphire waterjet orifices, what makes them great, and what your other options are.

Ruby and Sapphire Waterjet Orifices

As mentioned, waterjet orifices are often made of hard jewels such as ruby or sapphire. The base material used to grow these jewels synthetically (one which is used in the orifices), are same both for ruby and sapphire. They use synthetic corundum as the base material. However, chromium is added to ruby to provide its red pigment. Also, manufactured geometrics for each type of jewels can vary.

Corundum is used in various applications due to its extreme hardness. Ranking 9.0 on Mohs hardness scale and five times more abrasion resistant than carbide, corundum is a high-temperature tolerant, chemical resistant, and easy to reproduce material. So, they are extensively used where hard substances are required.

Being made of the same starting material, ruby and sapphire waterjet orifices are similar in hardness. However, rubies use a robust inlet edge radius of around 0.001”, so they can sometimes withstand greater abuse than sapphire ones, before failing.

However, rubies also create a shorter coherent jet stream. On the other hand, sapphires use “sharp-edge technology” that result in a long, smooth, coherent jet stream for cutting.

When to Use Sapphire or Ruby Orifices

Both ruby and sapphire can withstand harsh environments without much corrosion. However, even minor impact from debris in the high pressure system can affect these two and result in destroying their integrity.

Other options for waterjet orifices include diamond, but it is very expensive and can cost you hundreds of dollars for a single orifice. Having said that, diamond orifices however, are extremely hard. Diamond is the hardest substance known with a hardness rating of 10.0 on Mohs scale. So, these orifices obviously lasts hundreds of cutting hours. In comparison to 0-40 cutting hours of sapphire orifices, diamond ones definitely lasts longer.

But in scenarios where a manufacturer needs to change orifice combinations frequently, sapphire orifices can be a much less risky a choice. Frequently changing the nozzles increases the chance of debris entering and destroying the nozzle material. Chances of misplacing or losing it completely increases too.

In such cases, it is more convenient to work with ruby or sapphire orifices. Chances of losing it still remains but it would not be as catastrophic as losing a diamond orifice worth hundreds of dollars.

So, apart from ruby or sapphire waterjet orifices, your options include diamond as well. But sapphire orifices are more affordable and sometimes more convenient, as explained.