Hydraulic Fittings

How to Choose a Hydraulic Fitting

Selecting a fitting starts with matching the connection on both ends and confirming the assembly is rated above your working pressure. Work through these specs before ordering:

• Thread standard: JIC 37° flare, NPT/NPTF tapered pipe, ORFS (O-ring face seal), or SAE straight thread with O-ring boss (ORB). Mismatched standards will not seal even when sizes appear similar.
• Size / dash: Hydraulic sizes are called out in dash numbers (each dash equals 1/16 in), so a -8 fitting suits 1/2-in tube or hose. Confirm tube OD or hose ID, not just the nut size.
• Material: Carbon steel for most hydraulic pressure work, stainless for corrosion or washdown, brass for lower-pressure air and water lines.
• Configuration: Straight, 45°, 90°, tee, cross, bulkhead, or swivel — chosen by routing clearance and whether the joint must rotate during assembly.
• OEM cross-reference: Note any stamped part number or original manufacturer so an obsolete or proprietary end can be matched to a current equivalent.

Which Hydraulic Fitting Is Right for the Job?

The fitting family follows how the connection is made and held. Adapters convert between thread standards and sizes — the part you reach for when a port and a hose end do not match. Crimp Fittings are permanent hose ends swaged onto the hose with a crimp die, sized to a specific hose ID and series, and are typical on new hose assemblies built to length. Industrial Fittings cover pipe, brass, and air-line connections for shop plumbing and lower-pressure circuits where a full hydraulic-rated end is not required. If you are unsure which standard you are looking at, count the threads, check for a flare seat or O-ring groove, and compare against the dash size before committing to a die or thread form.

Complete the System

Fittings are the link between the components that move and hold fluid. Pair crimp ends with Hydraulic Hoses matched to the same series and pressure rating, and route those lines to Hydraulic Motors and Hydraulic Cylinders at the work end of the circuit. Where lines must connect and disconnect under field conditions, add Hydraulic Quick Couplers for fluid circuits or Pneumatic Quick Couplers for air tools and shop lines, both sized to match the adjacent fitting thread.

Cross-Referencing an Obsolete Fitting

Older equipment often carries fittings with discontinued part numbers, proprietary threads, or worn stampings that no catalog lists anymore. Northern Hydraulics has cross-referenced hydraulic parts since 1963, and that depth lets us match a thread standard, dash size, and seal type to a current equivalent even when the original number is gone. Send the stamped markings, a thread count, the flare or O-ring seat type, and the application, and we will identify the equivalent or build the assembly to spec. To start, request a cross-reference.