Different Types of Hydraulic Hose Fittings

 

Can you look at a hydraulic hose fitting and immediately identify its fitting design, type of fitting, sealing method, thread, etc.? 

If you can, that's excellent! If you can't, you are part of the vast majority. Many people don't know where to start, but we can help.  

You can learn more about the different types of hydraulic hose fittings, find the right one for you, and have it shipped to your shop or job site.

All you need to do is check out this guide. 

Where to Start 

There are countless hydraulic hose fittings on the market right now, and they're all doing the same thing: sealing and holding. However, you can't go out and buy one without knowing exactly which one you need. Using the wrong fitting could cause a major safety hazard. 

Permanent and Reusable Hydraulic Hose Fittings

The first question you should ask is whether you need a fitting that is reusable or permanent.  

Permanent fittings (or crimped fittings) are the more common option between the two. These require a crimping machine in order to attach them to a hose. They are easy to replace and remove, and they are the most reliable type of fitting. 

Reusable fittings connect to a hose with a wrench and a vise. This type of fitting is often left on the shelf due to its steeper cost and time-consuming assembly process.  

Port Connections and Fitting Ends

Now that you have decided on a reusable or permanent hydraulic hose fitting, you'll want to identify the port connections and fitting ends. This is a necessary step in order to begin assembling your tube or installing your hose. 

Port connections and fitting ends come in a variety of types which sometimes makes them seem difficult to identify. Luckily, there are short lists of these that are used the most often. The port connections and fitting ends that you'll need are likely included in the lists below. 

Here is a short list of common types of fittings. 

  • NPT/NPTF - Tapered inner and outer diameter making them self-sealing
  • BSPT (JIS-PT) - Standard fittings used internationally for making connections
  • Metric Taper - Has specific cylindrical diameters inside and outside 
  • SAE Straight Thread - 90-durometer O-Rings provide reliable sealing
  • ISO 6149 - diagnostic port applications made easy by its metric straight thread O-Ring port
  • JIS-B2351 - most often used for hose adapters, usually have BSP threads
  • DIN Metric - DIN is the German industrial standard
  • BDPP (JIS-PF) - Standard fittings which follow BSPT (JIS-PT) thread dimensions
  • 4-Bolt Flange - There are several options for these for normal-duty or heavy-duty

Here is a short list of common types of port connections.

  • 37-degree flare
  • 30-degree flare (Metric)
  • 30-degree flare (BSPP)
  • 45-degree flare
  • 24-degree flareless (SAE)
  • 24-degree flareless (DIN)
  • O-Ring Face Seal (ORFS)
  • 60-degree NPSM swivel
  • 60-degree cone (BSPP)
  • 60-degree cone (Metric)

The Sealing Method 

The three types of hose fittings that are most often used include the fittings described below. Hydraulic fitting types will change based on the three factors size, configuration, and thread types. 

Mated Angle - Mated angles are sold in many types. Fittings such as these are sealed with straight or parallel threads. When male and female threads connect, a seal forms as the two mating angle seats join each other. Two examples of these are JIC 37-degrees and SAE 45-degrees. 

Tapered Threads - These come in types of male and female. Male tapered threads have fitting threads on the outside. Female tapered threads have fitting threads on the inside. These hose fittings can have leakage issues as they are torque-sensitive. They are often imprecise, but it is wise not to use tape on tapered threads because it may contaminate sensitive areas.

O-Ring - There are three basic types of O-Rings. Face-seal (flat-face) O-Ring fittings, O-Ring flange fittings, and SAE straight-thread O-Ring boss fittings. O-Ring fittings are preferable to all-metal fittings because you are less likely to over or under tighten them.

Although these are the hydraulic hose fittings that are most often used, there are still several more.

The Fitting Design

Once you have found your sealing method, the next task is to observe the positions of the O-Ring, fitting termination, nose seat, and seat angle. 

In order to decide your seat angle, you will need a seat gauge. Note that female seats are often difficult to measure. You can determine a male seat's measurements by positioning the gauge on the sealing surface as the connection and gauge are parallel. 

Depending on your sealing method your O-Ring may be on the inside, outside, in the flange groove, or at the nose seat. Your nose seat may be inverted, flat face, or standard. 

Measuring the Thread

For this, you will need some calipers. Find the number of threads by the inch on the inside diameter (largest point of female threads) and the outside diameter (largest point of male threads). After noting these measurements you should now know your thread size.

Inspect Your Hoses and Fittings 

Make sure that your hoses and fittings have a secure connection. Be certain that they are not leaking by checking them often. Picking the right fitting can be a difficult task, and choosing the wrong one can result in a problematic outcome. 

What to Do Next 

Once you know what kind of hydraulic hose fittings you need, visit our site and browse our options. Find what's best for you!

You could have the correct hydraulic hose fitting packaged and shipped to your workplace from a company who has been supplying companies with quality products for more than two decades. 

If you still have questions about the hydraulic hose fitting options that are right for your equipment, please visit our contact page.