Our grease fitting relocation hoses come with a 1/8" NPT thread. This is the most common grease fitting thread in the U.S. All other bearing threads will require an adapter. You can find our adapters here and information on identifying your bearing's thread here.

Grease fittings come in many different styles. There are two grease fittings that are most commonly used in the U.S. These are the 1/8″ NPT thread and the 1/4″-28 SAE thread. Based on our own sales data, the approximate frequency of the different grease port threads in the U.S. are:

Grease Fitting Thread Gauge – The Easy Way

The easiest way to identify the thread on a grease fitting is to use a tool made specifically for this purpose. Grease fitting thread gauges are available from industrial equipment suppliers for around $50. Although convenient, you can identify your grease fitting thread without spending the money on this specialty tool.

Three Steps to Determining Grease Fitting Threads – Without a Thread Gauge

Measurement #1 – Straight or Tapered?

The first step in determining a grease fitting’s thread is to determine if the thread is straight or tapered. This is done by a visual check. Look carefully, a tapered thread is only tapered by about 3 degrees and is easy to miss if you aren’t careful.

Measurement #2 – Thread Pitch

The number of threads per inch is known as the thread pitch. The best way to determine thread pitch of a grease fitting is to compare the threads to something with a known thread. A thread pitch gauge is the ideal tool for this but you can also compare the grease fitting threads to a known bolt thread, pipe thread, or another grease fitting.

Place the known thread against the unknown thread. If the two threads engage, the thread is the same.  If they do not, the thread is different.

Measurement #3 – Thread Diameter

The last measurement you need is the outer or major diameter of the thread. A set of calipers makes this an easy measurement to take.

Finally, Find your Thread on the Chart Below

Dozens of different variations exist in grease fitting threads. We carry the necessary fittings and adapters to fit nearly every grease fitting port thread. These fittings cover more than 98% of the bearings found in the US. See the chart below to identify your grease fitting thread.

 

The bearing end of our hoses have a 1/8″ NPT Male thread. This thread will fit roughly 60% of U.S. grease ports as is. We have thread adapters available for most other bearing threads.

The grease fitting (zerk) end of the hose has an 1/8" NPT Female thread and comes with a zerk fitting installed.

The grease fitting end of the hose includes a bulkhead fitting that can be mounted anywhere using our Extension Hose Mounting Rail or can be mounted into any 7/16″ hole in material up to 1/2″ thick.

We measure hose length from the bulkhead to the end of the grease port thread. Please see this sketch.

We limit our grease extension hoses to 12' for two reasons.

(1) At lengths over 12' there is a possibility of over-greasing bearings. As grease is injected into the hose, the hose expands slightly and slowly contracts releasing the grease into the bearing over several minutes. If the lubrication tech is listening for the grease to enter the bearing, he will continue to pump grease into the hose. This will result in too much grease entering the bearing over time. The proper way to grease a bearing with our hoses is to inject a known amount of grease at each lubrication.

(2) Grease is made up of oil and a thickener. Grease stored inside the hose for long periods of time can separate. Longer hoses have grease stored for longer times as it travels the length of the hose. Every time the lubrication tech adds grease, the grease in the hose moves a little further down the hose. The longer grease is stored, the more likely separation is to occur.

We can manufacture longer hoses but want to make sure our customers are aware of these issues first. If you would like a quote for a hose assembly over 12 ft. long, please contact us here.

We are 100% web based. The best and fastest way to get ordering support is to contact us here.

Our extension hoses are useful anywhere grease fittings are difficult to reach.

Several common applications can be found here.

We're glad you asked. Yes, we have a collection of our best lubrication tech tips on our Grease Fitting Relocation Hose Tech Tips page.