Grease Fittings at

G.L. Huyett is a master distributor offering a wide variety of grease fittings for your fastening needs. Contact us to speak with our friendly, experienced Sales team to find just the right part for you!


Heritage Industrial Fittings


The G.L. Huyett Heritage grease fitting line is the broadest line offered anywhere and is designed to meet the most exacting standards.

Drive Type Fittings

Drive Type

Drive type fittings do not require a threaded hole decreasing the cost of installation. Some are equipped with a hex shoulder to assist in orientation.

Thread Forming Fittings

Thread Forming

Ideal for high-volume assembly line applications, thread forming threads are made out of case-hardened steel and designed for untapped holes.

Relief Vent Fittings

Relief Vent

Pressure relief valves release excessive pressure which may accumulate during operation of a bearing housing or gearbox. Install above fluid level.

Flush Type Fittings

Flush Type

Flush type fittings are for applications where a protruding greasing nipple may be impractical such as shafts, pulleys, and other rotating assemblies.

Grease Plugs


Standard plugs are manufactured from carbon steel utilizing a cold forming process. Hot forged and cast plugs are available upon request.

Grease Fitting Adapters


Adapters feature two different thread pitches and are used to connect dissimilar threads. Available in male to male, male to female, and female to female.

Breather Fittings


Breather fittings feature specially designed ports that allow air to move in-and-out, thus creating the effect of “breathing.” They have a special cap which reduces contamination.

Button Head Fittings

Button Head

Button head fittings are excellent for rugged applications such as conveyors, mining equipment, and agricultural equipment. The flat head minimizes damage from debris.

Elbow Adapters


Elbows are angled connectors used to plumb and make turns around obstructions. They usually have a male and female end and are available in 45°and 90°angles.

Grease Fitting Extensions


Extensions are used to provide additional clearance in hard to reach areas. They have the same thread pitch on both ends and are available either straight or angled.



Unlike other connectors, bushings adapt two threads without adding additional length. Commonly used to repair stripped holes and salvage the fitting.



What is a zerk grease fitting?

A zerk fitting, also known as a grease fitting or grease nipple, was patented by Oscar Zerk in 1929. It was introduced as an improved method of lubricating moving parts. Zerk fittings are permanently installed on bearing housings or mechanical components to serve as a lubrication point to feed precise amounts of grease into bearings and other moving systems. Zerk fittings come in variety of types, such as Drive In, Rivet, and Thread Forming. They can be manufactured using brass, stainless steel, and Monel® materials.

Where can I buy a zerk grease fitting?

G.L. Huyett offers its own complete private line of Heritage Industrial® grease fittings and accessories at the lowest distributor price! We are also a Master Distributor for Alemite®, Alemite Aerospace®, and Lincoln® brands. In addition, we offer a complete line of metric and international grease fittings. If you don’t find what you are looking for, call us today to speak with our friendly, experienced sales team.

How to attach a grease gun to a zerk fitting

First, ensure both the zerk fitting and the grease gun coupler are clean and free of debris and other contaminates. This will help ensure a secure connection between the fitting and the coupler. Next inspect the fitting to ensure there is no damage. If the fitting is damaged, you may want to consider replacing the fitting before continuing.

Once everything is clean and inspected, set coupler at an angle to fitting and while firmly pressing down, roll the coupler onto the fitting. You should feel the coupler clamp down on the fitting and click into position.

To remove the grease gun, ensure that the pressure has been relieved between the coupler and the fitting. If this does not happen on its own, tilt the coupler to approximately 15 degrees to break the seal. You may see grease expel from between the coupler and the grease fitting. Once pressure is released, continue tilting the coupler past 15 degrees while at the same time twisting back and forth. This should safely disengage the coupler from the fitting.

What size thread is used on a zerk grease fitting?

There are several components of threads on a grease fitting.


  • Thread Series
    Thread series is the thread "style" of a given grease fitting. There are many different thread series and each has specific attributes. Thread series can be either SAE Standard (also called taper thread), American Standard, Unified National, or Foreign Standard.
  • Thread Size
    Thread size is the nominal size of pipe that the fitting mates with. Originally, the size referred to the inside diameter of the pipe at a time when pipes had very thick walls. That is why a 1/8" pipe has a 0.393" actual outside diameter. G.L. Huyett carries sizes ranging from 0.18" diameter to 0.820" diamter and 6.0mm to 16.0mm in metric.
  • Thread Pitch
    Thread pitch refers to the distance "peak-to-peak" of each thread. Imperial and British standards call out threads per inch, while Metric standards specify thread pitch in millimeters.


Imperial vs Metric Thread Pitch

How to install "drive in" grease fittings

Drive in grease fittings, or Drive Type grease fittings, are installed into a non-threaded hole using a driving tool. A driving tool is a small cylindrical piece of metal with an opening on one end allowing for a secure fit over a grease fitting. To use the driving tool, simply insert the drive tool over the fitting and tap the opposite end with a hammer until the grease fitting is seated securely against the mating surface.

How to install "self-tapping" grease fittings

Self-tapping grease fittings, or thread forming grease fittings, can be installed using either a pre-existing or freshly drilled hole. For a new applications, start by drilling a hole into your part that is slightly smaller than the outside diameter of the grease fitting shank. It is encouraged to test fitment on a spare piece of material before permanently installing the fitting. Next, insert the shank of the fitting into the hole and begin tightening by hand while ensuring the fitting is perpendicular to the part it’s being attached to. Once started, use a grease fitting multi tool to finish the installation. Continue tightening until the grease fitting is seated securely against the mating surface of the part.

How to grease a zerk fitting

While grease fittings themselves do not require grease, the part they are attached to does. To grease the part, attach a grease gun to the end of the zerk fitting and pump until you feel resistance. It is a good idea to refer to your equipment’s service manual for recommended maintenance practices when possible.

There are many different types and designs of grease guns, and we offer lever, pistol, cordless, and pneumatic grease guns. We have a gun for practically any application. G.L. Huyett offers the following on our site.


  • Lever Gun
    Our standard lever gun is not only economical, but also provides the most volume per stroke as compared to other manual guns. A full range of interchangeable / customized features are available to suit your individual needs. ** Lever guns require two hands to operate. **
  • Pistol-Grip Gun
    Pistol-grip guns are good for use in close-clearance areas. Using just one hand, grease is pumped via a simple squeeze. Pistol-grip guns typically dispense less grease per stroke than a standard two-handed lever gun.
  • Cordless Gun
    Cordlress guns use rechargeable Lithium-ion batteries for complete portability and ease of use. Huyett guns come equiped with a carrying case and two batteries for extended use. ** Cordless grease guns are trigger operated, portable, and convenient. **


Grease Guns Available

How to replace a zerk fitting

Replacing a zerk fitting depends on the style and condition of the fitting being replaced. For standard threaded and thread forming zerk fittings, use a properly sized wrench, socket, or grease fitting multi tool to remove the fitting. A grease fitting multi tool is a great addition to any toolbox. The multi tool has 4 components: an extractor bit, a tap, and two socket ends to accommodate straight and angled fittings.

To remove drive type grease fittings, a slide hammer or pair of pliers can be used to remove the fitting. The fitting will not be able to be reused with these removal methods due to damage it will likely sustain.

Stubborn grease fittings that are broken or unable to be removed with a socket or wrench, can be removed using the extractor bit of a grease fitting multi tool. If necessary, begin by drilling a hole into the stubborn fitting to allow the multi tool’s extractor bit to fit inside. Be careful not to drill completely through the fitting as this could deposit metal shavings or other debris into the attached part. Once the fitting is completely removed, clean the threads using the tap on the multi tool.

How to grease a button head grease fitting

Button head fittings are popular in rugged applications where damage to protruding grease fitting heads is likely to occur. These low profile fittings can be greased using a button head coupler. Pull the coupler over the head of the grease fitting and pump until you feel resistance.

How to extend grease fittings

Grease fitting extensions are used to provide additional clearance for grease fittings in hard to reach areas. Grease fitting extensions are designed with external threads on one end and a flare with internal threads on the other. To install, thread the non-flared end of the extension into the grease fitting hole of the mechanical part you are servicing. Next, thread the grease fitting into the flared end of the extension using a socket, wrench, or grease fitting multi tool. Continue to tighten the fitting until the grease fitting and extension assembly are secure.

How to clean a grease fitting

Grease fittings tend to collect dirt and debris. Using grease caps is a preventative step in keeping grease fittings clean. However if grease caps are not in use, a lint free cloth can be used to wipe the fitting clean.

For clogged or blocked grease fittings, a grease fitting unblocker tool can be used. A grease fitting unblocker is specially engineered to quickly and easily unplug stubborn grease fittings. To operate, a light weight oil is injected into the tool’s reservoir. A plunger is then inserted and a tap from a hammer injects oil into the fitting, loosening the internal components.