Beyond super-duty (23,000 lb) sits the territory where standard catalogs end and engineered builds take over. Hamilton calls it Ultra Maxi-Duty. Caster Concepts calls it the 99 Series. Albion calls it 16TF. The names differ — the design philosophy doesn’t: dual-row tapered roller bearings stacked into kingpinless raceways, forged-steel construction in C-1045 grade, wheel diameters of 12″ minimum and typically 16-22″.
Wide-body aircraft engine cradles, large wing skin fixtures, and fuselage section transfer rigs at the assembly tier.
Steam turbine rotors, large generator stators, and nuclear reactor head transport in production and refurbishment.
Hot-rolled coil cradles, slab caster transfer cars, and finishing-line stage carts where individual loads exceed 80,000 lb total.
Pre-fab hull sections moved across yard between erection bays. Standard load tier where 4 casters at 30-40k each carry full sections.
Main battle tank assembly platforms, armored personnel carrier transfer between assembly cells.
Spent fuel cask transfer (~50,000-100,000 lb empty), reactor head movement during refueling. Engineered casters with full traceability.
The catalog leader at this capacity. Builds on the MD Maxi-Duty platform with dual-wheel construction, HPI™ Swivel Technology, and forged 1045 steel wheels machined with a slight crown to ease swiveling under load. Hamilton owns most of the aerospace and nuclear-grade installs in North America.
Drop-forged C-1045 steel yoke and top plate, integral forged kingpin, dual 22″ x 8″ wheels with 85A T/R polyurethane tread — the soft-poly approach lets the wheel rebound from weld slag and debris that would chunk-out a harder durometer. Common spec into stamping plants.
RWM’s 2-125 dual-wheel kingpinless tops out at 40,000 lb on 10″ forged steel wheels with tapered roller bearings and an 8.5″ x 8.5″ top plate. Albion’s 16TF runs comparable specs. Both popular in steel mill and foundry deployments.
Single-caster ratings above 40,000 lb leave the production catalog. Custom engineered builds reach 200,000 lb per caster for shipyard and powergen applications — these are quoted by application, not stocked.
Forged steel. The default. Rolls on steel rail or 6″ reinforced concrete without compression failure. Marks polished floors. Used in foundries, steel mills, and outdoor shipyards where floor marks don’t matter.
Hamilton Superlast 95A polyurethane on forged steel core. Premium spec where floor protection matters. The 95A durometer is firm enough not to deflect under cornering load; the forged steel core handles the 40,000 lb radial. Common in aerospace and pharma where polished concrete is the rule.
Soft 85A polyurethane (Caster Concepts T/R style). The right call for floors with debris exposure — stamping plants, foundries with slag risk, scrap metal yards. The soft poly absorbs and rebounds from chunks that would crack harder material.
Heat-dissipating polyurethane. Specified for sustained loads where standard polyurethane would soften and cold-flow (deform under continuous static load). Common in cold-storage and continuous-process facilities.
