Industrial Casters. Engineered for Spec.
Capacity scales linearly with diameter at the same material. 1,500 lbs/caster needs 6-8" depending on material. Above 2,500 lbs/caster you're in 8-10" minimum territory.
Diameter must be at least 4× the largest obstacle. 1/2" dock plate needs minimum 2" wheel; for clean operation use 8". Below 4x ratio, the wheel slams into the obstacle and stops.
Sensitive floors (epoxy, vinyl, hardwood) crack or indent under high contact-patch pressure. Larger diameter + wider wheel reduces PSI. Critical floors cap at 120 psi; concrete tolerates 500+ psi.
AGV/powered = 8" minimum (continuous duty needs minimum rolling resistance). Towed = 6" minimum. Manual push optimizes for ergonomics. Storage carts can go smaller for footprint.
8" caster runs ~9.5" overall. 6" caster runs ~7.5" overall. Workstation, under-shelf, and conveyor coupling applications often constrain deck height — that may force you to compromise diameter for clearance.
6" × 2" MAX Efficiency 85A on aluminum hub, maintenance-free precision bearings, kingpinless. 1,250 lb capacity. 7.5" overall mount height.
Shop 28AX06228S →8" × 2" MAX Efficiency on aluminum, maintenance-free, kingpinless. 1,500 lb capacity. 9.5" overall mount height. Best balance of capacity, force reduction, and obstacle clearance.
Shop 28AN08228SL →8" × 2" Maroon Kingpinless ergonomic. 1,500 lb. 10.13" overall mount height. Best for frequent direction changes — kingpinless raceway eliminates the highest-failure component.
Shop 110AX08228SX →Custom 7", 9", 11", 14", 16" diameters available. Ergo Poly on Aluminum hubs, custom durometer, custom width. Send your envelope, get a sized quote with engineering review.
Wheel diameter must be at least 4× the largest floor obstacle for clean roll-over. A 1/2" dock plate transition needs minimum 2" wheel; for clean operation use 8" or larger. Below 4x ratio the wheel slams into the obstacle and stops, requiring lift to clear.
Sensitive floors (epoxy, vinyl, hardwood) crack or indent under high contact-patch pressure. A 1,500 lb load on a 4" × 2" wheel concentrates ~375 psi on the contact patch. Same load on 8" × 2" drops to ~190 psi. Critical floors (cleanroom, hardwood) cap at 120 psi; sensitive floors (epoxy, vinyl) at 200 psi; standard concrete tolerates 500+ psi.
Crown tread: lower contact patch area, ~8% lower rolling resistance, best for ergonomic applications and frequent maneuvering. Flat tread: maximum contact patch, lowest floor pressure, best for static load distribution and machinery moves. Most ergonomic 6" and 8" Albion MAX Efficiency wheels use crown profile by default.
Width drives capacity at the same diameter. A 6" × 2" wheel rates 50-70% higher than 6" × 1.25" of the same material. Wider wheels reduce floor pressure (psi at contact patch). Trade-off: wider wheels need more swivel torque and more space envelope. For most industrial carts, 2" width is the sweet spot.
Caster height scales with wheel diameter. A 4" caster runs ~5.5" overall; an 8" caster runs ~9.5"; 10" runs ~12". For workstation carts, conveyor coupling, or under-shelf transport, the deck height constraint may force a compromise. Use the deck height field in the calculator to enforce upper limits.
12"+ wheels are used in aerospace ground support, foundry transfer carts, large die handling, military rough-terrain dollies. Above 4,000 lbs per caster, 12" becomes the minimum standard. Custom 14"-16" diameters exist for specialty heavy industry. Request custom diameter.
No for standard carts. Mismatched diameters cause uneven load distribution and accelerated wear. Exception: intentional designs like dock-stair carts where front wheels are intentionally larger. Always use uniform diameter and width for standard applications.
Larger wheels run quieter — they bridge floor imperfections instead of dropping into them. An 8" polyurethane on standard concrete is roughly 5-8 dB quieter than a 4" of the same compound. For library carts, healthcare, and clean rooms, larger diameter is the easiest noise reduction.
The 28-series MAX Efficiency uses 85 Shore A urethane on aluminum hub with maintenance-free sealed bearings — engineered for the lowest rolling resistance in production. At the same 8" diameter, MAX Efficiency runs 30-40% lower force than standard poly on iron with roller bearings. The premium pays back through ergonomic compliance and reduced operator fatigue claims.
Escalate for: custom diameters between standard sizes (e.g., 7", 9", 11"), high-deflection floors (mezzanine grating), specialty hub materials (forged aluminum, nickel-plated), or any application above 5,000 lbs/caster. Submit your spec for engineering review.
