Getting the right wheels on your benches and work tables can make all the difference in creating a mobile shop design that works well and lasts for years.
Discover what you need to consider when choosing the right caster for your project.
Caster Factors to Consider
There are several elements you’ll want to spec when choosing the best caster for your needs.
We’ll cover all of them here.
The caster factors to consider are:
- Load capacity
- Wheel material
Below are charts and formulas to help you figure out how much your bench weighs, plus the gear it will hold.
Formula for Weight to Caster Ratio
The easiest way to figure out the caster load capacity you need is to use this formula:
Total weight of bench and gear it will hold divided by the number of casters.
Total Bench Weight
Figuring out the total weight of the bench is easy.
If you built it yourself, then you likely have a cut list or at least a rough materials list.
Use the charts below to simply add up your bench weight from how much material you used.
Common Dimensional Lumber Weight
NOTE: The chart below assumes you are using green lumber. Kiln dried weighs less. Pressure treated weighs more.
Here’s an easy way to determine your plywood weight.
Since it’s not likely you’ll be using a full sheet for the top and bottom, but rather portions, then figure your square footage for each.
Then check the chart below for the weight per sheet and determine your percentage.
Since everyone will load their bench with different items, you’re on your own for calculating this part.
But here’s a tip to make it easy.
Look up your item on Amazon.
If it’s a tool, search for it online. The product specs should be listed on sites like Amazon, and hardware stores.
If you plan to also store lumber, even scraps, you’ll need to figure that in as well.
Caster Load Capacity by Size
A LOT goes into determining how much weight a caster can bear.
The 2 main load factors include:
- Wheel diameter
- Wheel material
We’ll cover wheel material choices more in a moment, but for this section, we will assume that you’ll be using standard duty, rubber wheels.
Below is a chart of how much weight each caster can bear, on average.
NOTE: Be sure to read the specifications of the caster you plan to purchase to be sure it meets your needs.
2 Most Popular Caster Sizes
So, 4 casters at 2″ can hold a total max weight of 600 lbs.
And 4 casters at 3″ can hold a total max weight of 1000 lbs.
I’m betting that these will be the two caster sizes that will work for most of your shop projects.
Keep in mind that the height of the caster is listed for the wheel size.
That height does not include the bracket/mounting part of the caster.
Rule of thumb is to add at least 1/2″ to the wheel size for the overall height.
From the chart above, it’s obvious that larger casters can handle more load capacity, in general.
But let’s say you have a bench that needs casters that can handle 200 lbs each. Then you have a choice of 3” or 4” casters.
Which do you use?
Consider the overall height of your bench.
Now factor in whether you will have a lower shelf.
If so, then the distance between the top of the lower shelf and the bottom of the top apron will be impacted by your caster height choice.
That’s really the only part of the leg length that you can adjust.
So, if need a specific height between those two, for something like a vacuum dust collector, or a set of drawers, or other tool storage, then you’ll need to be mindful of your wheel choice.
See these posts for tips on determining overall bench height.
Mitre Saw Station: Tips for Building – has tips on how I determine my final bench height plus distance between the top and lower shelf.
Easy 2×4 Workbench Legs – shows how I figured in caster height for determining total leg height.
Wheel Material Considerations
There are three main considerations with the material you chose for your casters:
- Scuff marks
- Chemical resistance
Rubber wheels can be either hard or soft rubber.
The harder the rubber is, the more weight it can bear, and the easier it will roll.
Plus, softer rubber is prone to getting a flat spot if the bench sits in one place too long.
So, if your bench is super heavy, then you definitely need harder wheel material.
Black rubber wheels tend to leave scuff marks – and I can most definitely attest to this!!!!
The gray and/or red rubber wheels usually don’t leave scuff marks.
Get the anti-scuff ones if you can – you’ll thank me later.
Some rubber melts when it comes into contact with certain chemicals, like grease and solvents.
Maybe grease and oil are not things you have to be concerned with in a woodworking shop.
But, you may use mineral spirits for stripping, sealing, painting, or cleanup.
Just be sure you don’t spill any on the wheels, or roll the bench through that stuff.
If you regularly have these liquids on the floor, then look for chemically resistant wheels. And expect to pay more for them.
You’ll want to give some thought to how you plan to mount the casters to the legs.
There are 3 types of caster mounts:
- Bolt bracket on bottom
- Bolt bracket on side
This type of mount requires drilling a hole in the center of the leg, which is only feasible in a 4×4 post. It also requires a brad hole tee or other type of threaded insert, and maybe even a locking washer between them.
While this may sound like a lot more work than screwing on a bracket, it has the advantage of allowing you to adjust the height of each caster.
Most garage shop floors are not perfectly level. In fact, many are sloped slightly to aid in draining water off your rain-soaked car out toward the door.
Be sure to read up on best methods for installing this type of caster if you decide to do it.
And look for a package deal that includes the threaded insert too.
Bolt Bracket on Bottom
This is likely the cheapest, and most common way of attaching casters to a workbench.
And this is the type of mount I chose for my benches too.
Bigger wheel sizes also have bigger mounting brackets, meaning the plate is bigger.
That will most definitely come into play, depending on how you plan to attach the wheels to the leg!
Bigger wheel brackets also have bigger mounting holes.
So be sure you can get the right size lag screw for it. And you do want lag screws instead of regular wood screws. They are more heavy duty and longer.
Bolt Bracket on Side
These are generally found on the fancier, and more expensive casters.
And almost all come with either brakes, or a way to totally disengage the caster. That means you can set the bench solidly down on its legs and just use the wheels to move it when needed.
The down side of these casters, besides the price, is that they offer a tripping hazard because they are sticking out from the legs.
I guess if you never walk around the ends of your bench, then they aren’t as much of a hazard.
But, if your bench will be part of a longer series of tables, these could get in the way of placing the bench tops side by side with no gap.
This has one advantage, and one disadvantage.
Swiveling casters allow you to easily roll the bench in any direction. That’s the advantage.
The disadvantage is that the bearings may lower the load capacity.
So, if you need a 2” caster, you may need to give up the swivel if you have a heavier bench load.
Honestly, I’d go for the swivel, if you can.
They will likely cost a little more than the non-swivel in the same brand and size.
You must have brakes on your casters!!!
That, or get the side mount ones that you can disengage.
It’s just too dangerous to have your workbench suddenly, and unexpectedly move on you.
But, you may not need them on every wheel.
Casters with brakes are more expensive.
You could get away with only half of the casters having brakes. And simply mount the ones with brakes on the same side, preferably the one that is easy for you to get your foot on, like the front.
Another thing to consider is access.
If you’re mounting a 2” caster centered on a 4×4 post, you may have a hard time getting your toe on the brake lever. It will be fully under the post.
A 3” caster is pretty easy to access under a 4×4 post, no matter which way it is turned except with the brake turned totally toward the inside.
I hope this article has helped you chose the perfect caster for your project.
Be sure to leave a comment and let us know what combo worked best for you.