Caster Load Capacity: 33 to 3,307 lbs. How to Choose
Posted by Kyle Kim on Sep 28th 2026
What the number on a caster product page actually means
Choosing the right caster starts with reading one number correctly. A product page shows a load capacity figure. The question is what that figure covers: one caster, or a set of four. Get that wrong and the selection is wrong before anything else has been decided.
That single ambiguity is the most expensive mistake in caster purchasing, and it is entirely avoidable once you know what to look for.
Two product types appear in the CarryMaster catalogue, and both publish load capacity in the same format. Leveling casters and non-leveling casters are rated the same way, so the selection method below applies to both. For how leveling casters work and when they are the right choice, see the leveling casters guide.
What follows covers the per-unit distinction, the seven published CarryMaster capacity ranges with exact figures, what shifts as the rating climbs, and where the catalogue ends.
Per unit, not per set of four
The most common source of confusion when comparing caster product pages is not the specifications. It is the denominator behind the number.
Some listings publish a capacity figure for a set of four casters. Others publish the figure per individual caster. A multi-pack listing showing "1,000 lbs capacity" is ambiguous unless it states explicitly whether that figure applies per wheel or to the pack as a whole. Comparing a per-unit number from one page against a set-of-four number from another is not a valid comparison, and the result is almost always undersizing.
How CarryMaster publishes the figure
CarryMaster product pages state load capacity per unit, using the notation lbs/ea or the phrase "per unit." Of 142 products in the current catalogue, 138 carry a published per-unit capacity figure. Those figures run from 33 lbs per unit to 3,307 lbs per unit across 35 distinct values.
The cut sheets go one step further. They state both conventions side by side, in the form:
1,103 lbs/ea | 2,205 lbs w/4
That reads as 1,103 lbs per individual caster, or 2,205 lbs for a set of four. Both numbers describe the same product. A buyer reading only the with-4 figure and comparing it against another supplier's per-unit figure would be weighing 2,205 against 1,103 and reaching the wrong conclusion.
Why the gap matters in practice
When a product page lists a capacity figure without naming the denominator, there is no reliable way to know which convention is in use. The difference is not marginal. A per-set figure for a four-caster application is roughly four times the per-unit figure for the same load. Choosing on a misread denominator leaves the individual casters rated at roughly one quarter of what the equipment requires.
The practical check: whenever a capacity figure appears on a product page, confirm whether it is stated per caster or for a set. On CarryMaster pages the lbs/ea notation makes it explicit. On the cut sheet both figures are printed together, so either reading can be verified against the other.
Sizing from the published figure
Once the correct per-unit number is in hand, the next step is applying a safety factor and accounting for how the load actually distributes across the casters. That calculation, including the safety factor and the three-caster assumption, is covered in full in the caster load capacity sizing guide. What follows is about matching a known requirement to the right published range.
The seven CarryMaster load capacity ranges
CarryMaster publishes load capacity figures across seven bands. The table lists each band, how many products sit in it, the actual published per-unit range, the wheel materials available, and the mount options. Every figure comes from the live product pages.
Browse the full catalogue filtered by rating at CarryMaster casters by load capacity.
|
Range |
Products |
Published per-unit range |
Wheel materials |
Mount options |
|---|---|---|---|---|
|
27 |
33 to 88 lbs/ea |
Polyurethane 27 |
Flange 13, Stem 14 |
|
|
16 |
110 to 198 lbs/ea |
Rubber 15, Nylon 9, PA6 8, TPR 6 |
Flange 7, Stem 7 |
|
|
31 |
220 to 298 lbs/ea |
Rubber 16, PU 15, PA6 12, TPR 12 |
Stem 16, Flange 15 |
|
|
16 |
353 to 485 lbs/ea |
PU 9, PA6 7 |
Flange 12, Stem 2 |
|
|
17 |
529 to 992 lbs/ea |
PU 13, PA6 4 |
Flange 15, Stem 2 |
|
|
23 |
1,102 to 1,764 lbs/ea |
Nylon 12, PA6 8, PU 4 |
Flange 21, Stem 2 |
|
|
8 |
2,205 and 3,307 lbs/ea |
PA6 7, Nylon 2 |
Flange 7, Stem 1 |
What each band is built for
Under 100 lbs (27 products, 33 to 88 lbs/ea). All 27 products in this band use polyurethane wheels. CarryMaster describes the application as light loads on trolleys and carts, and medical devices. Stem and flange are split almost evenly at 14 and 13.
100 to 200 lbs (16 products, 110 to 198 lbs/ea). The widest wheel material spread in the catalogue: rubber, nylon, PA6 and TPR all appear here. Flange and stem are evenly split at 7 each. Worth checking when the application calls for a particular wheel surface and the rated load sits below 200 lbs per caster.
200 to 300 lbs (31 products, 220 to 298 lbs/ea). The largest band by product count. All four wheel materials appear, and stem holds a slight edge at 16 of 31. Buyers replacing a caster at this rating have the broadest selection available.
300 to 500 lbs (16 products, 353 to 485 lbs/ea). The material range narrows to polyurethane and PA6, and flange dominates at 12 of 16. Medium Duty labelling begins to appear in product titles at this level, since the published Medium Duty range starts at 353 lbs per unit.
500 to 1,000 lbs (17 products, 529 to 992 lbs/ea). Flange is the clear majority at 15 of 17, and polyurethane accounts for 13 of the 17 wheel specifications. Medium Duty labelling is common across this band.
1,000 to 2,000 lbs (23 products, 1,102 to 1,764 lbs/ea). The largest band in the upper half of the catalogue. Nylon leads at 12 of 23, PA6 at 8, polyurethane at 4. Flange accounts for 21 of 23.
Over 2,000 lbs (8 products, 2,205 and 3,307 lbs/ea). Two published values only. PA6 appears on 7 of 8 products and nylon on 2, and 7 of 8 are flange mount. The single product rated 3,307 lbs per unit is the AC-1800F.
What changes as you move up the ranges
Moving from the lowest band to the highest is not only a change in the number. Three things shift consistently across the catalogue as the per-unit rating increases.
Wheel material
Polyurethane dominates the low end. All 27 products under 100 lbs use polyurethane wheels. As capacity rises the mix changes: by the 1,000 to 2,000 lbs band nylon leads at 12 of 23 with PA6 at 8, and above 2,000 lbs PA6 accounts for 7 of 8 products.
That is a pattern in the published catalogue rather than a rule about performance. For how the materials actually compare, see the caster wheel materials guide.
Mount type
Stem mounts are more common at the low end, at 14 of 27 products under 100 lbs. Above 2,000 lbs only 1 of 8 is stem, with flange taking 7 of 8. In the 1,000 to 2,000 lbs band flange accounts for 21 of 23.
Where mount type is a constraint, the stem vs flange casters guide covers that decision in detail.
Brake availability
Brake options are not evenly distributed across the capacity range. Under 100 lbs, 9 of 27 products include a brake. Above 2,000 lbs, 2 of 8 do. Across the full 142-product catalogue, 87 products carry a published brake specification.
What that means for buyers: where a brake is a requirement, filter for it inside the target capacity band rather than assuming it will be available at every rating.
|
Shift |
Low end |
High end |
|---|---|---|
|
Wheel material |
Polyurethane dominant |
PA6 and nylon dominant |
|
Mount type |
Stem common |
Flange dominant |
|
Brake availability |
9 of 27 under 100 lbs |
2 of 8 above 2,000 lbs |
Where the CarryMaster range ends
The CarryMaster catalogue tops out at 3,307 lbs per unit. That figure appears on one product, the AC-1800F. The next published value below it is 2,205 lbs per unit, which applies to 7 of the 8 products above 2,000 lbs.
How CarryMaster labels its products
CarryMaster labels its products Light Duty and Medium Duty only. Across 142 products the published duty labels break down as:
-
Light Duty: 42 products, covering 33 to 265 lbs per unit
-
Medium Duty: 37 products, covering 353 to 1,764 lbs per unit
-
No duty label stated: 63 products, spanning 110 to 3,307 lbs per unit
Those are the labels printed on the product pages, and they are the only ones applied to CarryMaster products here.
What this means if your requirement is above 3,307 lbs
Requirements above roughly 3,300 lbs per caster fall outside what CarryMaster currently publishes. That boundary is stated plainly because a buyer with a requirement in that range is better served knowing it immediately than being pointed toward a product that cannot carry the load.
A published ceiling is more useful than an implied one. CarryMaster publishes an exact per-unit figure on 138 of its 142 product pages, and that precision is only worth something if the limit is stated with equal precision. For a requirement above 3,307 lbs per unit, contact the Zambus team for advice on the right route.
Choosing the range you need
Most buyers arrive at this decision from one of two directions.
New purchase. Starting from a known approximate equipment weight, identify the band that covers the per-unit requirement once a safety factor has been applied, then open the filtered collection for that band. The CarryMaster load capacity hub allows browsing directly by rating.
Replacement. A caster that has failed carries a published rating on its label or its original product page. Match that per-unit figure to the correct band, then confirm the mount type and wheel size match the original as well. CarryMaster publishes which mount types and wheel materials are available at each rating level.
When a requirement lands near the top of a band, look at the next band up. The 500 to 1,000 lbs band reaches a published ceiling of 992 lbs per unit, and the band above it opens at 1,102 lbs. A requirement close to 992 lbs is technically inside the lower band while leaving almost no margin, where the same requirement in the band above has room to spare. Band labels describe a filtered collection, not a rating, so the figure that decides the selection is always the published per-unit number on the product itself.
Where the rating on a failed caster is unclear, or where a requirement sits close to the boundary between two bands, the Zambus team can confirm the right specification before an order is placed.
Contact the Zambus team by phone at (973) 777-4922 or through the contact page.
Frequently Asked Questions:
Is caster load capacity per wheel or for the whole set?
Check the listing format before comparing anything. A multi-pack listing showing "1,000 lbs capacity" is ambiguous unless it specifies per wheel or per pack. CarryMaster product pages use lbs/ea to signal a per-unit figure, and CarryMaster cut sheets print the per-unit and with-4 totals side by side. Where a listing does not specify, treat the figure as unconfirmed until the supplier confirms it.
What load capacity do I need for a 1,000 lb machine?
The per-unit rating depends on how many casters carry the equipment, how the load distributes across them, and what safety factor the application requires. CarryMaster publishes 138 per-unit figures ranging from 33 to 3,307 lbs. The full sizing method, including the safety factor, is set out in the caster load capacity sizing guide.
What is the highest load capacity CarryMaster offers?
The highest published per-unit load capacity in the CarryMaster catalogue is 3,307 lbs per unit, on a single product, the AC-1800F. The next published value is 2,205 lbs per unit, available on 7 products. Requirements above 3,307 lbs per caster fall outside what CarryMaster currently publishes.
Why do caster capacity figures sometimes differ between a product page and a cut sheet?
The difference is usually the denominator, not a discrepancy. CarryMaster cut sheets print two figures for one product: the per-unit capacity, for example 1,103 lbs/ea, and the with-4 capacity, 2,205 lbs w/4. A product page may show only one of the two. The cut sheet resolves which figure applies to a single caster and which to a set.
What does "lbs/ea" mean on a caster specification?
"lbs/ea" means pounds per each, the load capacity of one individual caster. CarryMaster uses the notation on 138 of 142 product pages to make clear that the published figure is a per-unit rating rather than a total for a set of four. Where lbs/ea appears, the number beside it applies to one caster.
Do I need the same capacity on all four casters?
Matching the rating across all casters is standard practice in four-caster applications. Load distribution is rarely equal, which is why sizing methods assume three casters carry the full load rather than four. Mixing ratings within a set is not advisable, because the lowest-rated caster defines the practical limit for the whole application.
What happens if I choose a caster rated below the load?
A caster carrying more than its published per-unit rating is operating outside its specification from first use. The published figure is the ceiling for that product under the stated conditions, not a target. The cost of undersizing is almost always higher than the cost of selecting the correct range from the CarryMaster catalogue at the outset.
How do I choose a replacement for a caster that has failed?
Match the replacement to the published per-unit rating of the original rather than to an estimate. The lbs/ea figure appears on the failed unit's label or its original product page. Then confirm the replacement matches on mount type, flange or stem, and on wheel size. CarryMaster publishes both attributes at every capacity level.
Which wheel materials are available at higher load capacities?
PA6 and nylon dominate the upper end of the CarryMaster catalogue. In the 1,000 to 2,000 lbs band nylon accounts for 12 of 23 products and PA6 for 8. Above 2,000 lbs, PA6 appears on 7 of 8. Polyurethane, common in the lower bands, covers 4 of 23 products between 1,000 and 2,000 lbs and none above 2,000.
How do I find CarryMaster casters by load capacity?
The CarryMaster load capacity hub filters the full catalogue by rated capacity. Each band has its own filtered collection: under 100 lbs, 100 to 200 lbs, 200 to 300 lbs, 300 to 500 lbs, 500 to 1,000 lbs, 1,000 to 2,000 lbs, and over 2,000 lbs. Selecting the band that matches a per-unit requirement shows every CarryMaster product published at that rating.