How Do I Choose Hydraulic Fittings?

Three Things To Know When Choosing Hydraulic Fittings
Trying to choose the right hydraulic fitting can sometimes feel like you are on a game show. Close your eyes, turn around three times and pick one. The best you can hope for is that the one you land on is not a complete fail. With all of the different types of threading and seal options, it can be overwhelming, to say the least. There really is a method to the hydraulic fitting madness. Here are the three things you need to know when choosing your next hydraulic fitting.

1. Understand the Pressure Rating

Required pressure ratings are increasing and there are a lot of fittings that will not meet the new requirements. Manufacturers are choosing o-ring seals and DIN (German Institute for Standardization) metric fittings to address the higher pressures. Many fittings such as JIC (Joint Industry Council) fittings and NPT (National Pipe Taper) threads are not rated for these higher pressures nor the increased vibration. By understanding the pressure rating and vibration level you can choose the hydraulic fitting that meets the requirements of your equipment.


Pro Tip: Part AvailabilityJIC and NPT fittings have been the standard for quite some time. That being said, they are easier to find than some of the newer fittings. If you need one of the newer fittings you may not be able to just pick one up. It’s always good to plan around the possibility of having to order one.

1. Know the Reliability and the Risks

Manufacturers are moving toward o-rings and DIN metric fittings for more reasons than just pressure ratings. They are also more reliable when it comes to reducing the risk of cracks and leaks. NPT pipe threads have always been a popular choice because you can quickly fix a leak by just tightening the connection. Unfortunately, that also leads to over tightening which causes cracked fittings. The elastomeric seal that is gained by using the o-ring seal prevents leaks and the DIN metric fitting prevents over tightening.


Pro Tip: VersatilityDespite the changes taking place from a manufacturer and rating level, there are still some benefits to using other types of fittings. The versatility of the JIC fitting is important to note. There is a large variety of these fittings and connectors that allow easy conversion to different ports and sizes.

1. Know STAMP

STAMP stands for Size, Temperature, Application, Media, and Pressure. You need to understand all of these factors to ensure that you are selecting the best fitting for the job. By understanding the application of the fitting you will be able to choose the fitting that will not only be the right size but will also function under the temperature and pressure conditions. You also need to understand how the fluid going through your system will affect the material of the fitting. The chemical compounds of the fluid can react with the material and cause havoc on your fittings and your system. Most fittings are available in a variety of materials so you can find one that is compatible with your system.


Finding the right hydraulic fittings and seals for your equipment shouldn’t be rocket science, but with all of the evolving standards and applications, it can certainly feel like it. Follow these tips and you will find that making the right selection isn’t that hard. All it takes is a little know-how and an understanding of your system to make choosing your hydraulic fittings a breeze.