Application 1 — machinery bases and equipment skids
Static-heavy, moves rarely
Mobile machine bases, generator skids, compressor mounts
Equipment that sits under load for weeks then moves once. The caster has to hold a heavy static load without flat-spotting the wheel, then roll smoothly when the move finally happens. Forged-steel-core polyurethane is the standard — it carries the static load without cold-flow and rolls clean when needed. Total-lock brakes are mandatory; this equipment should never drift.
Application 2 — die, mold, and tooling carts
Heavy, frequent, impact-prone
Stamping die carts, injection mold transfer, tooling dollies
Dies and molds get moved between press and storage constantly, and they get dropped onto the cart, not lowered gently. This is the application that justifies kingpinless construction at this tier — the repeated drop-loading deforms a kingpin shaft over time. Kingpinless distributes the impact across the full raceway. Forged steel wheels handle the point loads.
Application 3 — transformer and electrical equipment dollies
Heavy, slow, precision placement
Transformer dollies, switchgear carts, battery banks
Electrical equipment that has to be positioned precisely and then stay exactly where it’s placed. Smooth-rolling roller-bearing swivels for the controlled move; total-lock brakes for the final placement. Non-marking polyurethane keeps the substation or electrical room floor clean.
Application 4 — large in-plant transfer carts
Heavy, towed, continuous duty
Tugger-towed transfer carts, line-side delivery carts
Carts pulled in trains behind a tugger, often around the clock. Towing multiplies the dynamic load and the cornering force — this is a 3–4× safety factor application. Kingpinless swivels with tapered roller bearings handle the sustained towing cycles; standard kingpin casters wear out fast in tow-line service.
What changes structurally at 1,251-2,000 lb
Three things become baseline rather than upgrade. Kingpinless swivel construction — the failure-resistance math now clearly favors it, especially for impact and towing applications. Roller or tapered-roller bearings — precision ball bearings are at their limit here. And forged-steel wheel cores — cast iron still works for pure static loads, but forged steel is the standard once impact or towing enters the picture. Pricing reflects it: this tier costs meaningfully more per caster than the medium-duty band below, because the construction genuinely changes.
The CasterHQ load-rating ladder — per caster
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Under 350 lb · Light duty — Office, display, AV, healthcare carts
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351-675 lb · Light-medium — Service carts, tool carts, utility trolleys
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676-1,250 lb · Medium duty — Industrial carts, racks, workbenches
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1,251-2,000 lb · Medium-heavy — Machinery bases, die carts, equipment (you are here)
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2,001-4,000 lb · Heavy duty — Large machinery, transfer carts, tooling
1,251-2,000 lb tier FAQs
Can these still be hand-pushed?Marginally, at the bottom of the tier, on a smooth level floor, with two people. Realistically this is tugger or powered-assist territory — design the move method into the equipment.
Is kingpinless mandatory at this tier?Not mandatory, but strongly favored — and effectively required for die carts and tow-line carts where impact and cycling are constant. For pure static-load machinery bases, a heavy kingpin caster can still work.
What safety factor for a towed cart?3–4×. Towing adds dynamic load, cornering force, and the shock of train start-stop. A towed cart sized at 2× will fail early.
Cast iron or forged steel wheel core?Forged steel once impact or towing is involved. Cast iron is acceptable only for pure static-load equipment that moves rarely and gently.
My math lands above 2,000 lb — what changes?You move into heavy-duty territory, where kingpinless and forged steel are universal and four-caster sets are always powered. See the 2,001-4,000 lb tier.
Match the build to the application
Tell us what the equipment is, how it moves (hand, tugger, towed), and how often. We’ll match the right construction.
Call 844-439-4335
