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Stud & Stack

Reference

Casters: the component that decides whether the box moves

Load per caster is arithmetic and nobody does it. Wheel diameter decides whether a loaded cabinet crosses an expansion joint or stops dead at it.

By Scooter M.

Published September 1, 2026

Last reviewed September 1, 2026

A close-up of a heavy-duty metal caster wheel

Divide the loaded weight by the number of casters. A 604 lb cabinet loaded to about 900 lb on six casters is 150 lb per wheel; on four it would be 225. Diameter matters separately: a 6-inch wheel crosses a garage expansion joint that stops a 3-inch wheel dead.

Load per caster, and why six beats four

This is the arithmetic nobody does. Caster ratings are published per caster, and the load on each one is the total weight divided by the number of wheels - assuming the floor is flat and the load is even, neither of which is quite true.

One published 56-inch combo set is 604 lb empty on six 5 x 2 in casters. Loaded to a realistic 900 lb, that is 150 lb per wheel. The same box on four casters would be 225 lb per wheel - a 50 percent increase in load on each one, which shows up as more rolling resistance, more flex in the base rail, and faster bearing wear.

Work out your own drawer

What is going in one drawer

Add what you would actually put in your heaviest drawer. Every weight below is a published product weight, rounded to the pound.

  • Mechanic's socket set, 200 pc24 lb0
  • Combination wrench set, 22 pc11 lb0
  • Impact socket set, 1/2 in drive18 lb0
  • Screwdriver set, 20 pc6 lb0
  • Pliers and cutters, 8 pc9 lb0
  • Cordless drill plus two batteries8 lb0
  • 1/2 in torque wrench6 lb0
  • Hammers and pry bars14 lb0

0 lb

In that one drawer

96 lb

Working load at 80% of 120 lb

604 lb

Loaded box, 101 lb per caster

Add something above and the arithmetic runs.

The loaded-box figure assumes your remaining drawers average 45 percent of the heaviest one, which is our own assumption rather than a published figure — the shallow top drawers are never as heavy as the deep bottom ones. Change the empty weight and drawer count to match the box you are actually looking at. How we work these out.

It also matters for uneven floors. On a floor that is not perfectly flat, a four-caster box rocks between three contact points at a time, so the momentary load on one wheel can be well above the average. Six casters spread it and the box sits more solidly.

Diameter is about obstacles, not weight

A bigger wheel rolls over a step of a given height more easily than a small one, for straightforward geometric reasons: the larger the wheel radius relative to the obstacle, the shallower the effective angle it has to climb. Practically, in a garage, that means expansion joints and drain channels.

Wheel diameterWhere you see itWhat it handles
2-3 inLight cabinets and workbenchesA smooth flat floor and nothing else
5 inMainstream tool cabinetsMost garage floors; struggles at a wide expansion joint
6 inBetter cabinets and heavy benchesExpansion joints, drain channels, small thresholds
8-9 inModular rolling basesGravel, curbs and job-site ground

Published examples: one 56 in cabinet uses six 5 x 2 in casters; another uses four 6 x 2 in. Modular rolling bases publish 8 in (ToughSystem 2.0) and 9 in (PACKOUT) all-terrain wheels because they are designed to leave the shop floor.

Width matters too, and for a different reason

A 5 x 2 in caster is 5 inches in diameter and 2 inches wide. Width spreads the load across the floor, which matters on soft surfaces - asphalt in summer, an old garage floor with a soft screed, or anything with a coating. A narrow wheel under 200 lb marks a coated floor; a wide one is far less likely to.

It is also why you should not leave a heavy loaded box parked on the same spot on an epoxy-coated floor for years. The load does not go away because nothing is moving.

Locks: what actually locks

  • Wheel brake stops the wheel rotating. The caster can still swivel, so the box can still shuffle sideways.
  • Swivel lock stops the caster turning. The box can still roll.
  • Total lock does both, and it is what a loaded cabinet actually needs.
  • Toe lock is a total lock you can operate with a boot - worth a lot when both hands have tools in them.
  • Fixed casters do not swivel at all. Two fixed at the back and two swiveling at the front is a common and good arrangement: the box tracks straight instead of crabbing.

Moving a loaded box safely

  1. Close and lock every drawer first. A drawer that rolls open mid-move shifts several hundred pounds of load and is how boxes tip.
  2. Push, do not pull. Pushing puts your weight behind the box; pulling puts the box's momentum behind you.
  3. Cross joints square on. A wheel hitting an expansion joint at an angle catches one caster and turns the box.
  4. Never move it on a slope with the drawers loaded high. Weight up high plus a slope is exactly the tipping case. Heaviest things in the bottom drawers.
  5. If it will not roll, do not force it. A caster that has flat-spotted from years parked in one place needs replacing, not shoving.

Replacing a caster

It is a straightforward job and the main trap is the mounting pattern: cabinet casters are usually plate-mounted with a four-bolt pattern that varies by maker. Measure the plate and the bolt spacing before ordering, and match or exceed the original load rating.

Also match the height. A replacement caster half an inch taller than the others puts the cabinet out of level and loads the other wheels unevenly, and on a bench it changes the working height. Bench height.

Common questions

How much weight can tool box casters hold?

The published rating is per caster, so divide your loaded weight by the number of wheels. A 604 lb cabinet loaded to 900 lb sits at 150 lb per wheel on six casters, or 225 lb on four. Nobody publishes the loaded weight because it depends on your tools.

Are 6-inch casters better than 5-inch on a tool box?

For obstacles, yes. A larger wheel climbs a step of a given height at a shallower effective angle, which in a garage means crossing expansion joints and drain channels. For load, width matters more than diameter.

Why do some tool chests have six casters?

To reduce load per wheel and to sit more solidly on an uneven floor. A 900 lb loaded box is 150 lb per wheel on six casters and 225 lb on four, and on an uneven floor a four-caster box rocks between three contact points at a time.

How do I move a loaded tool chest safely?

Lock every drawer first, push rather than pull, cross expansion joints square on, and never move it on a slope with weight in the high drawers. A drawer rolling open mid-move shifts hundreds of pounds and is how boxes tip.

Sources

Every figure on this page either comes from one of these sources or is computed on the page from a figure that does. If you think one of them is wrong, tell us — we publish corrections.

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