Caster Stems: Types and How To Choose the Right One for Your Application
Stem casters are essential for rolling everyday objects ranging from office chairs to warehouse carts and pallets. While you shop the extensive inventory of stem casters by Caster Central on our website, be sure to explore the multitude of caster stems and envision how you can use them to help your business thrive.
The Functions of Casters
Before we can consider the different types of stem casters, we should start by discussing the core functions of casters and how they shape design choices and features in modern furniture and equipment.
An ideal caster should allow a person to push a wheeled conveyance (such as a cart) with minimal effort and maximum control over speed and trajectory. Casters should be maneuverable but stable enough so the operator can maintain control.
In addition to these essential features, stem casters should also be able to:
- support sufficient weight
- be long-lasting
- be easy to keep clean
The design of caster stems impacts the functionality of casters in many respects, which we discuss in more detail below.
The Anatomy of a Stem Caster
The stem of a stem caster is where everything comes together. The top of the caster stem anchors into the furniture or equipment that the caster mounts on to.
At the other end of the caster stem, along with a nut and washer for some designs, is the fork that holds the wheel in place. Some caster designs feature a protective wheel cover that surrounds the wheel in place of a fork. The cover often includes a brake lever. Some stem casters have two wheels that attach to the central stem rather than a fork surrounding a single wheel.
Stem Casters vs. Plate Casters
The main alternative to stem casters is plate casters. Plate casters bolt or screw onto furniture in four places at the edge of the plate, rather than in a central stem. Plate casters are best for heavy-duty applications that require the casters to bear heavy loads. A disadvantage to plate casters is that they can take more effort to install.
Stem casters can work well for furniture with thin legs, like office chairs. It might not be feasible to mount a plate on the bottom of a chair leg, but most chair legs are wide enough to fit a single hole for a screw or bolt.
Types of Stem Casters
Although all caster stems serve the same function, they mount differently and have advantages for specific applications. The stem you choose can influence the weight capacity, the tightness of the caster's fit, and the performance of the caster.
Expanding-adaptor stems use a slightly more complex design but provide a secure fit and allow the caster to roll smoothly over uneven surfaces. The expanding adaptor is a cylindrical stem, somewhat thicker than typical caster stems. The stems expand slightly when you insert them into a tubular opening in the furniture leg, so friction holds the stem in place.
A grip-neck caster stem is a metal stem with a head and a slightly narrower neck at the top. To install a grip neck caster, you would drill a hole in the furniture leg and insert a plastic socket that fits over the stem head. The socket grips the neck and holds the caster in place. Grip-neck casters are economical caster solutions for light-duty applications like small rolling trays and office chairs.
Another name for grip-neck stem casters is wood-furniture casters because the design typically attaches wheels to wooden furniture.
Grip-ring stems are similar to grip-neck stems, except that the shape of the tip of the stem is different. They narrow just below the head. The stem fits into a pre-drilled socket within the furniture leg. A metal ring within the socket fits into the narrow part of the stem, holding the caster in place.
Threaded-stem casters are simple designs that use a threaded bolt that protrudes upward from the caster assembly. If the furniture leg has a matching home with threads, you can insert the caster into the leg as easily as threading a screw.
Bolt Hole Casters
Bolt hole casters do not have an integrated stem as part of the caster. Instead, the caster contains a hole you can fit a bolt through. When you install the caster, you slide a bolt through the hole in the caster and secure it with a nut and washer,
Casters come in different sizes. To avoid installation mistakes, damage to furniture, or caster failure, double-check that you have the appropriately sized hardware.
For instance, if your furniture has pre-drilled sockets for your casters, the stem casters need to be the right diameter to ensure a secure fit. For threaded stems and bolt-hole casters, be sure that the thread count and the diameter of the bolt are compatible with the furniture leg.
The caster stem is essential to giving the caster stability and maneuverability, but it is also a structural weak point of the design. Before you purchase or install stem casters on your equipment or furniture, accurately assess the load capacity you need and make allowances for unbalanced loads, dynamic loads, and impact forces.
Overestimating the weight capacity that you need could increase the cost of new casters, but underestimating loads could lead to a sudden failure of a caster, which could lead to broken equipment, employee injuries, and potential legal liability. Some forethought beforehand will ensure that you get the most out of your casters.
Caster Stem Sockets
The best way to confirm that your caster will have a good fit with your furniture or cart is to purchase matching caster stems and sockets. If you are retrofitting furniture with aftermarket casters to replace broken or faulty casters, you might have to replace the socket if you cannot find a stem caster that matches your existing furniture.
Leveling mounts are similar to caster stems, but their role is to keep equipment flat and steady rather than to help it move. If you are using casters to move heavy equipment from place to place in your business, plan to secure that equipment when you store or operate it. Either install leveling mounts on the bottom or bolt equipment to the wall for safety.
Stem Caster Quality
The casters you use for your equipment should have precisely crafted components and consist of durable materials. Precision is particularly crucial for caster stems because they will not work right if they don't mount properly.
Lesser-known brands of casters might look nice at first glance but could have faults or manufacturing defects that might not become apparent until you try to install them or when they break after a short time in service. Look for established brands like Colson, Pemco, and Shepherd.
Find the Perfect Caster at Caster Central
Once you familiarize yourself with the different types of caster stems in our inventory, you'll be ready to choose a caster or combination of casters and caster wheels for your business. At Caster Central, we stock reputable brands in many sizes, designs, and materials, so you are virtually guaranteed to find what you need.
Spend your maintenance and renovation dollars wisely by choosing casters and caster-mounting hardware that will serve your business well for years. Our experienced customer support staff at Caster Central looks forward to answering your questions about various types of caster mounts. Call us at 1-800-445-4082 for more information today.