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A Comprehensive Review Of Stem Casters

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Attachment options for casters can seem overwhelming. This is especially true when dealing with stem casters. Stem casters are commonly found in the home, restaurants, hospitals, and any other place where space is an issue. Below, you’ll find some useful information that will help you select the right caster.


  • A lot of furniture manufacturers see casters as an afterthought and use cheap casters for their applications. This makes purchasing aftermarket casters a worthwhile, and sometimes necessary investment.
  • Stem casters are typically used when space is limited and a top plate won’t fit on the application. As such, the majority of stem casters are considered light to medium duty.
  • Hollow kingpin casters are casters with a hole in the top of the fork where a stem can be field installed. This is an excellent option if you can’t find a caster that has the stem you need.
  • Measurement is the key component. You may know what type of stem you need but have you measured the application to make sure it will fit? Be as accurate as you can. Tools like calipers, bolt gages, and measuring tape will be your best buddies.



grip ring stem - ice caster
grip ring stem - vintage caster

Most office chairs and light furniture use grip ring casters. They are traditionally smaller and light duty. The brass ring on the stem compresses as it is inserted into the mounting hole and then expands (you’ll hear a click) to keep it in place. These can be removed with a firm hand or with the help of a pair of pliers.


grip neck stem - chair caster
grip neck stem - phenolic caster

Grip Neck stems are used in conjunction with metal or plastic sockets to attach a caster to a wood application. As a result, installation usually requires a drill to make a hole in the wood.


threaded stem - cc apex caster

This is probably the most common stem type. They're easy to attach but sometimes hard to match. Measuring threaded stems can be confusing but we're here to help. On our website we list the measurement of a threaded stem like this:

3/8"-16 x 1-1/2"

  • 3/8” is the diameter of the stem.
  • 16 is the thread pitch or thread count per inch. This can be an issue when dealing with casters that use the metric system of measurement.
  • 1-1/2” is the length of the stem (as is the case with all stem casters, the length of the stem is not included in the overall height of the caster because when attached the stem is hidden inside the application).


round stem - poly on iron caster
round stem - cc apex caster

Round stems casters are commonly found on scaffolding and have a hole in the stem where a cotter pin securely attaches it to the application. These tend to be heavier duty compared to other types of stem casters.



Expanding adapter casters are basically threaded stem casters with a rubber grommet attachment that when compressed inside a hollow tube or leg expands and secures it to the application.

When picking the appropriate expanding adapter it’s important to measure the inner diameter of the tube or leg you’re attaching it to. Also note that the listed size of the expanding adapter is slightly smaller and expands slightly larger to accommodate the fit into the application. Therefore, a 1” expanding adapter is approximately 0.928” before expansion and approximately 1.029” after expansion. This allows the stem to fit into the leg loosely and then be expanded to the desired size.


-Measuring Stem Size

-Anatomy of a Stem Caster

-Measuring Overall Height

-How to Replace Office Chair Casters

-How to Measure and Install an Expanding Adapter

-Types of Stem-Mount Caster Rigs

With this knowledge we hope you can now safely choose a stem caster that’s right for your application. Finally, if you get stuck, don’t hesitate to reach out to our knowledgeable solutions staff for any of those tricky situations.

For even more information about stem mount casters, visit Types of Stem-Mount Caster Rigs.