Fitment Help

Is this the right flow restrictor for your equipment?

The 1/2" BSPP (G1/2) Inline Hydraulic Flow Restrictor is designed for compatible 1/2" BSPP parallel hydraulic thread connections. This is a common thread style on many imported tractor implements, including some Chinese flail mowers, ditch bank mowers, side-shift mowers, hydraulic top links, grapples, and other implement cylinders.

However, not every hydraulic connection is BSPP. Before ordering, it is important to verify the thread type on your hose, fitting, cylinder, or coupler connection.

This product fits:

1/2" BSPP hydraulic connections
G1/2 parallel thread hydraulic connections
Compatible female-to-male BSPP inline installations
Hydraulic connections where a .030" fixed flow restriction is appropriate

This product does not fit:

1/2" NPT tapered pipe thread
JIC flare fittings
SAE ORB / O-ring boss fittings
Metric hydraulic threads
Quick coupler body size alone

BSPP vs NPT

BSPP is a parallel thread. NPT is a tapered thread. They are not the same and should not be forced together.

BSPP fittings typically seal with a bonded washer, sealing face, or similar sealing surface. NPT fittings seal by thread taper. If you try to install the wrong thread type, the fitting may leak, damage the threads, or fail to seal properly.

Quick coupler warning

The size of your hydraulic quick coupler does not automatically tell you the thread type behind it. A quick coupler may have BSPP, NPT, JIC, ORB, or another threaded connection depending on the hose and fitting setup.

When this restrictor is useful

This flow restrictor is commonly used when a hydraulic cylinder moves too quickly or abruptly. Examples include:

Ditch bank flail mower angle cylinders
Side-shift flail mower cylinders
Hydraulic top links
Hydraulic side links
Grapple cylinders
Other tractor implement cylinders that need slower movement

Need help confirming fitment?

If you are not sure what fitting you have, please contact us before ordering. Include clear photos of the fitting, hose end, coupler, or cylinder port. A close-up photo of the threads and sealing surface is usually the most helpful.