Grease Guns Explained – What Are They, Different Types, What Are They Used For & Buying Guide

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Grease guns are common workshop tools used for lubrication purposes. There are different types available depending on the task you have at hand. This article will provide you with all the relevant information on the different types of grease guns, what they’re used for, and a full buying guide!

Table of Contents

What is a Grease Gun?

A grease gun is a very common workshop and garage tool that is used for lubrication purposes. The grease gun applies lubricant through an aperture to a specific point, usually from a grease cartridge to a grease fitting or otherwise referred to as a nipple. The channels behind the grease nipple lead to where lubrication is required.

The aperture may be of a special type that fits closely with a receiving aperture on any number of mechanical devices. This close-fitting design of the apertures makes sure that the lubricant is only applied where it is needed.

Types of Grease Guns

There are a number of grease guns available in the market. Each of which offers a unique set of features and varying capabilities. The four grease guns that should be understood:

  • Lever grease gun
  • Pistol-grip grease gun
  • Cordless grease gun
  • Pneumatic grease gun

Lever Grease Gun

Lever-operated grease guns have a mechanical advantage in that they’re known to develop higher output pressure when compared with pistol-grip grease guns. Although lever-operated grease guns tend to have a comparatively low-pressure output, they are generally known to have a higher output per stroke.

The amount of grease that comes out of its aperture will depend on how far you push the lever. Lever grease guns are probably the most common of all grease gun types. They are typically suited to applications that involve large clearances, like greasing large bearings.

It is generally advised that for industrial applications you should go for a lever-operated grease gun that has a higher output pressure, but lower volume per stroke.

Here’s an example of a lever grease gun readily available on Amazon:

Pistol-Grip Grease Gun

Pistol-grip grease guns have a handle that resembles a conventional pistol. The handle features an integrated trigger that you press in order to push grease out of the gun. This allows for an easy one-handed operation.

However, pistol-grip grease guns have a less mechanical advantage compared to lever grease guns as they only develop a limited amount of pressure. Because of this, they probably will not be the right choice when you are looking for a close-tolerance, metal-to-metal fit.

Pistol-grip grease guns are only suited for DIY automobile maintenance projects and for other non-industrial, projects. The more powerful versions of pistol-grip guns may be able to deliver about 500 psi of grease pressure on average, with a comparatively lower output per stroke.

Here’s an example of a pistol-grip grease gun readily available on Amazon:

Cordless Grease Gun

Cordless grease guns run on rechargeable batteries. They are known to be convenient, intuitive, and highly portable due to this. Even though these units are battery-powered, some of the leading models can produce a significant amount of power. The DeWalt 20v max grease gun, as can be seen below, is capable of producing up to 10,000 PSI of pressure.

Since you do not need to operate any levers, you will find such a grease gun far easier to use and be able to complete lubrication projects faster and more efficiently. However, the length of work you can get out of a model will depend on its battery performance. It may not be appropriate for use in applications that requires you to grease extended periods of use.

Here’s an example of a cordless grease gun readily available on Amazon:

Pneumatic Grease Gun

Pneumatic grease guns are some of the most powerful and efficient grease guns you can buy in today’s market. They will complete each lubrication job faster and minimize the fatigue associated with the work.

Such units are powered by compressed air, from an air compressor, making them far more reliable, especially when working on industrial lubrication projects. The air pressure is highly regulated, which results in less wear and tear on the parts and components.

The drawback to pneumatic grease guns is that they are very noisy in operation, meaning you may head to wear ear protection gear while using one. Provided you have a long air hose, pneumatic grease guns can be rather flexible and versatile.

Air grease guns, or pneumatic grease guns, use compressed air to apply pressure to an air piston, which drives the grease piston and forces lubricant out of the coupler into a grease fitting. By depressing the gun’s trigger, a steady flow of lubricant is dispensed. Typically, pneumatic grease guns are rated up to 6,000 PSI.

Grease Gun Buying Guide

Since grease Guns come in different types and sizes, it is important for you to get one that is suited for the intended application. For instance, you will need a larger, powerful Pneumatic Grease gun for industrial applications.

For DIY lubrication applications, a smaller pistol, cordless lever model may suffice. Ideally, you will require a gun that delivers just the right amount of grease to whatever part you are lubricating. Other than having to select the right type of grease gun, as previously discussed, you should also pay attention to the following factors:

  • Maximum operating pressure
  • Reloading options
  • Accessibility

Maximum Operating Pressure (PSI)

Regardless of the type of grease gun, they are designed to deliver a certain amount of pressure. A gun that is capable of delivering a high fluid pressure will not disappoint in any project. You must consider the pressure requirements of the tasks you will be using your gun for.

For example, high pressures are required to pump grease into clogged fittings, especially if you are using a heavy lubricant or during cold weather environments. You must make sure that you choose a model that offers just a little more pressure than you actually need so you have some leeway.

Reloading Options

Another important consideration is how you prefer the grease gun to be refilled. Different grease guns support different grease reloading mechanisms, with the 3 common ones being:

  • Cartridge loading
  • Suction loading
  • Bulk loading

Cartridge Loading

A grease gun that uses this mechanism is refilled using packaged cartridges. Although this method is a lot easier and more convenient, it is costlier when compared to the other loading options. This method also has a negative impact on the environment when it comes to the disposal of the empty cartridges.

Suction Loading

The suction loading mechanism requires that the grease gun be filled manually, often from a bulk drum. To do this, you will need to open and insert the end of the gun into the grease in the bulk drum and then pull the lever to suck grease into the gun.

Such a grease gun is only suited for use with lighter-grade grease types. Heavy grease types are difficult to load into these types of grease guns. Suction loading can be a strenuous task.

Bulk Loading

Bulk loading is the cleanest, easiest, and most affordable grease loading mechanism of these three. You will need bulk loader fittings, a bleeder valve, bulk loader couplers, and a bulk filler pimp to refill your grease gun using the bulk loading method.

The grease gun loader fitting should be pressed into the loader coupler on the pump and then after loading, the bleeder valve should be used to relieve the gun of any leftover air that may have entered during the reloading process. A tip here is to use a follower plate that will minimize air pockets in your bulk grease.


While shopping for a new grease gun, you need to be sure of what you’re using it for. Will the gun be used to pump grease in confined spaces or more open spaces? You need to worry about the accessibility, and clearance of the points of application.

The design of your preferred grease gun should feature a compatible coupler, depending on where you will be using the grease gun. The coupler should allow for easy access to the points you need to grease. For enhanced flexibility of the gun, you may need to buy additional accessories to optimize its true potential.

Pneumatic Grease Guns Available on Amazon

I have picked out a couple of the best pneumatic grease gun that are readily available on Amazon. The first is this Lincoln pneumatic grease gun which has a maximum pressure of 6,000 PSI. The Lincoln grease gun pneumatic offers a variable speed trigger which provides excellent grease flow control.

This LockNLube is an Amazon choice that offers this 2-in-1 pneumatic grease gun with single-shot & continuous modes.

How to Load a Grease Gun

Most grease guns tend to operate on the same principle mechanisms, but be sure to read and understand all the manufacturer’s directions before use which you can find within the user’s manual. The following can be used as a guideline:

How to load a grease gun step-by-step guide

  1. Pull the plunger back

    Pull the plunger back (there is a spring inside being compressed when you do this—this is important to know later) and rest it on the catch in the tool body. Then unscrew body from the head.

  2. Remove tube

    If the gun has an old grease tube in it, remove the tube. If the tube is jammed carefully and slowly release the plunger to push the tube out. Re-latch the plunger once you can get a grip on the tube.

  3. Check gasket

    Check that the gasket that seals the tool body to the actuator head hasn’t gotten buried in grease and thrown away with the old tube.

  4. Insert tube into tool

    On the new tube, remove the plastic cap and insert the tube into the tool—open end toward the plunger.

  5. Re-assemble the tool

    Remove the pop-top or foil. This lid is astonishingly sharp, be mindful. Re-assemble the tool.

For tools with no bleeder valve, the unit must be primed, or burped, to get any air out. Thread the unit back together and back it off one turn. Release the plunger. You may actually have to push it down through the grease. Tighten the tool and dispense grease onto a piece of cardboard until it flows burp-free.

If the handle doesn’t resist the pressure you put on it, there is air in the tool. Keep pumping until the flow is uninterrupted. On the other hand, for units with bleeder valves, the air can be evacuated through the valve.

Using a Pneumatic Grease Gun: Safety Tips

Here are a number of tips that can help ensure you’re looking after your pneumatic grease gun properly, and advise on how to use pneumatic grease gun.

  • Calculate the proper amount of grease needed for the lubrication of bearings based upon the calibrated delivery volume of the selected grease gun
  • Calibrate grease guns regularly to ensure the proper delivery volume
  • Use extreme caution when loading grease into the grease gun to ensure that contaminants are not introduced
  • Ensure that the proper grease is used at every grease point
  • Make sure the grease gun is clearly marked to identify the grease with which it should be charged. Do not use any type of grease other than that which is identified
  • Always make sure the dispensing nozzle of the grease gun is clean before using
  • Clean the grease fitting of all dirt before attaching the grease gun. Inspect and replace damaged fittings. It is helpful to use grease-fitting caps to keep them clean, but still wipe fittings clean before applying grease.
  • Use a vent plug on the relief port of the bearing to help flush old grease and reduce the risk of too much pressure on the bearing
  • Grease guns should be stored unpressurized in a clean, cool and dry area and in a horizontal position to help keep the oil from bleeding out of the grease

Here’s a useful YouTube demonstration on a pneumatic grease gun not working. A very common issue is pneumatic grease gun won’t work.

FAQs (Frequently Asked Questions)

Are air-powered grease guns any good?

Air-powered grease guns are some of the most powerful and efficient grease guns you can buy. They will help you to complete each lubrication job faster and minimize the fatigue associated with the work. The air pressure is highly regulated, which results in less wear and tear on the parts and components compared to other types of grease guns.

Do grease guns use compressed air?

Pneumatic grease guns are powered by compressed air, from an air compressor, making them far more reliable, especially when working on industrial lubrication projects. They use compressed air to apply pressure to an air piston, which drives the grease piston and forces lubricant out of the coupler into a grease fitting. By depressing the gun’s trigger, a steady flow of lubricant is dispensed.

What is a pneumatic grease gun?

A pneumatic grease gun is a grease gun powered by compressed air. Although they need to be connected to an air compressor, they tend to offer the greatest power of all the different types of grease gun, along with boosted efficiency.

If you’re wondering how to plumb an air compressor setup, visit our guide!

If you have any questions regarding grease guns, please leave a comment below, with a photo if applicable, so that someone can help you!

By Aidan Weeks

A passionate Mechanical Engineer with endless enthusiasm for fluid power - building off the back of over 18 years of high quality contribution and discussion stimulated by Bill Wade here at About Air Compressors. With both practical and theoretical experience in pneumatics and hydraulics, I'm putting my knowledge to work - and working my grey-matter through my research, assistance and publishing work here at About Air Compressors. Feel free to reach out any time! P.S. A HUGE shout out to Doug who really offers such great value to all visitors to About Air Compressors - once again, feeling like I'm standing on the shoulders of GIANTS by getting to work alongside such a great community

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