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Custom made to order. All sales final.
Each Hamilton product is custom manufactured for your order and ships in about 4-6 weeks. Please confirm all specs before checkout, since made-to-order items aren't eligible for returns, exchanges or refunds. Need help? Call 844-439-4335 or email info@casterhq.com and we'll verify fit for you.
Order processing
In stock. Orders placed before 12pm CT (Mon–Fri) typically ship the same or next business day from our Mansfield, TX warehouse.
Shipping method
Because of its size and weight, this item typically ships LTL freight on a pallet. Smaller add-on items may ship parcel. Freight cost is calculated by destination and shown before payment, or quoted for large orders.
Payment & procurement terms
New to CasterHQ? Open an account or request terms and send your resale or tax-exemption certificate before ordering so it is applied at checkout.
Volume pricing & quotes
Quantity discounts apply automatically — no codes needed. For large, recurring, or custom requirements, request a bulk quote and our team will confirm pricing, lead time, and total landed freight upfront.
Returns & warranty
Stock items carry a 30-day return policy in unused, resalable condition. Made-to-order and custom items are non-returnable once production starts. All products carry the manufacturer's warranty against defects.
Central & Southern U.S.: typically 1–2 business days
East & West Coasts: typically 2–3 business days
Remote areas and freight deliveries may take longer.
For pallet freight, scheduled releases, or blanket purchase orders, contact our team and we'll confirm total landed cost before you commit. Direct line: 844-439-4335.
This Hamilton R-ZFMD-1255POYB-ULTRA 12" x 5.5" Poly Rigid Caster – 5800 lb is rated to 5800 lbs per caster. Size a set by dividing the total load by the number of casters, and for uneven floors assume 3 of 4 casters carry the load. Keep continuous-use loads within about 75-80% of the rating.
This caster runs a Polyurethane wheel with a 5-1/2" tread width. Polyurethane protects finished floors, rolls quietly, and resists most chemicals while carrying heavy loads.
This caster uses a top-plate mount with a 8-1/2" x 8-1/2" plate. Measure your existing mounting holes before ordering; if you are replacing casters, match the bolt pattern - most standard patterns interchange across brands.
This is a Rigid caster. Rigid casters track straight for directional stability. For most mobile equipment we recommend 2 swivel + 2 rigid, or 4 swivel with at least 2 brakes.
Rated for -70°F to 175°F. Operating outside the rated range can reduce wheel life and load capacity, so match it to your environment (wash-down, freezer, oven-adjacent, etc.).
The Polyurethane wheel performs best on smooth to semi-smooth floors including sealed concrete, tile, and epoxy. For non-marking or clean-environment needs, ask us about matching tread options.
The overall height (floor to top of plate or stem) is 15-5/8". Account for it when checking equipment clearance, dock height, and ergonomic working height.
We accept purchase orders and offer Net 30 on approved accounts, ACH, and all major cards, plus tax-exempt ordering with a resale or exemption certificate. Volume discounts apply automatically; request a bulk quote for large or recurring orders. Stock items carry a 30-day return policy in unused condition (made-to-order items are non-returnable once production starts).
Application guidance for load margin, wheel materials, and swivel construction. Confirm ratings against your duty cycle, floor, and temperature before final spec.
Start with total system weight (payload + structure + fixtures), divide by casters that actually share the load, and keep continuous working load per caster at or below roughly 75% of catalog capacity (~25% margin). Heavy-duty kingpinless frames are often used on uneven floors, docks, and towed trains where dynamic load transfer is common — do not assume perfect four-caster share. If impact, drop-offs, or shock loading is expected, treat the margin as a floor, not a stretch goal, and confirm capacity at the wheel diameter and tread you select on this PDP. Dynamic and side loads are separate from static catalog ratings; call out towing or AGV duty when you quote so we can sanity-check the configuration.
Stay with polyurethane when floors are relatively smooth, temperatures stay inside the PU service window, and you want floor protection plus rollability. Move to phenolic, glass-filled nylon, or other high-temp / high-hardness options when heat, certain chemicals, or very high point loads push past what standard PU can sustain. Kingpinless construction solves swivel durability under thrust; it does not raise the wheel’s temperature or chemical limit. Use the wheel material and temperature fields on this product (and sibling SKUs) to match the environment — heat duty and side-thrust duty are independent selection axes.
Kingpin swivels concentrate clamping and much of the axial stack through one pin. Towing hitches, AGV corrections, and side scrub introduce lateral and moment loads that work that pin and the race faces harder than hand-pushed carts. Typical early wear modes include kingpin stretch or hole elongation, race brinelling, and increasing swivel play. Kingpinless designs replace that single-pin stack with a machined or forged raceway that carries thrust through the race path, which is why they are the usual spec for powered towing and higher side-load industrial carts. Pair kingpinless swivels with a wheel and bearing package rated for the same duty — the swivel upgrade alone does not fix an undersized tread or bearing.
$3,294.00
| Identification | |
|---|---|
| Part Number / SKU | R-ZFMD-1255POYB-ULTRA |
| Replacement Wheel Part No | W-1255-POYB-ULTRA-1-1/4 |
| Core | |
| Load Capacity | 5800 lbs |
| Wheel Diameter | 12" |
| Wheel Width | 5-1/2" |
| Floor to top of mounting plate (or stem shoulder).Overall Height (OAH)Floor to top of mounting plate (or stem shoulder). | 15-5/8" |
| Rig Type | Rigid |
| Brake | No Brake |
| Mounting | |
| Mount Style | Plate |
| Plate Size | 8-1/2" x 8-1/2" |
| Recommended Mounting Bolt | 5/8" |
| Wheel | |
| Wheel Material | Polyurethane |
| Wheel Color | Natural Poly on CNC-Machined 1045 Blank |
| Bearing Type | Precision Sealed Ball Bearing |
| Construction | |
| Frame / Finish | Platinum Powder |
| Temperature Range | -70°F to 175°F |
| Unit Weight | 131 lbs |
| Compliance | |
| Buy American | Yes |
