Types of Hydraulic Conversion Fittings

As in many industries, the fluid power industry is rife with various terms for the same object. This is certainly the case with hydraulic conversion fittings. Sometimes they are also called conversion adapters. The purpose of a conversion fitting is to change one type of connection to another, between hose, tubing, pipe or a combination of the former.

Straight steel hydraulic conversion fitting

There are two considerations when determining the correct conversion fitting for your job. The first is to determine the actual conversion; what two different threads do you have on your hands? Second, you must determine the configuration of your fitting.


Examples of some hydraulic conversions include:

  • JIC to British
  • Metric to American
  • British to O-Ring Flat Face
  • Japanese (JIS) to JIC

These conversion fittings come in multiple configurations, such as: 


Straight conversion adapters do not feature any bends. They have a thread on one side of the adapter and a different thread on the other side of the adapter. They are often used in racing and industrial applications.

90 Degree

These fittings, whether conversion or not, are also referred to as elbow fittings. As one would expect, 90 degree fittings bend at a right angle, which make connections of components that are perpendicular to each other a breeze.

45 Degree

Also called elbow fittings due to their bend, 45 degree fittings connect components that do not exactly align, and can accommodate slight bends. Conversion fittings with a 45 degree angle are only one of the options for a 45 degree fitting.


A tee conversion fitting features three ports: one on the top and one on each side. Be confident before you buy that you properly identify which port needs which thread. (Use the measure twice cut once principle).

Depending on your application, you will need to determine the material of your conversion fitting as well. Steel can withstand higher pressures as compared to SAE standards, feature high corrosion resistance and are extremely rust resistant. 

Understanding conversion fittings (or adapters) comes down to two simple principles: conversion and configuration. Once you have those down, it just becomes a matter of determining your supplier!