Product Catalog
Mold-on Rubber Wheels — Vulcanized Rubber Treads on Cast Iron and Aluminum Cores
Updated 2026-11
Mold-on rubber is the construction answer to a simple conflict: rubber gives the quiet, shock-absorbing, floor-protecting ride, but a wheel also needs a dimensionally stable hub, bore and load path. The published manufacturer descriptions are consistent — cushion rubber treads vulcanized to cast iron cores (or die-cast aluminum cores), the rubber affording a cushion effect to the load while the core carries it. The result is a wheel that is highly shock-absorbing and quiet while dampening vibration.
Published per-line reference bands split by core: the heavy-duty cast-iron-core line spans 340-2,500 lb at 3-1/4 to 16 in with 90-95 Shore A rubber; the softer-tread cast-iron line spans 900-2,570 lb at 12-16 in with 70-85 Shore A rubber; the aluminum-core line spans 250-600 lb at 4-8 in with 80-83 Shore A rubber. Per-line values confirmed at quotation, never merged into one family promise.
Specifications
| Type | Rubber tread vulcanized (molded) onto core; cast iron and die-cast aluminum core constructions |
|---|---|
| Reference capacity bands (manufacturer reference) | Heavy-duty cast-iron core: 340-2,500 lb at 3-1/4 to 16 in (90-95 Shore A); soft-tread cast-iron core: 900-2,570 lb at 12-16 in (70-85 Shore A); aluminum core: 250-600 lb at 4-8 in (80-83 Shore A) — per-line bands, never merged |
| Bond (manufacturer reference) | Vulcanized rubber-to-core bond — chemical and mechanical adhesion, not glue; core surface preparation and cure discipline decide bond life |
| Ride character (manufacturer reference) | Shock-absorbing, quiet operation, vibration dampening; harder 90-95 Shore A treads still cushion while carrying heavier bands |
| Temperature note (industry reference) | Rubber treads are the temperature-limited element of the assembly; state ambient and contact heat in the RFQ so the compound and core are matched |
| Lead time | 15–20 days (custom configurations 30–40 days) |
| MOQ | 200 pieces (standard catalog items ship in smaller quantities) |
| Warranty | 18 months |
Capacity and durometer figures above are published manufacturer line bands kept separate by core and durometer tier — a line band is a reference for class positioning, never a tenant family promise. The rating for your configuration is stated on the quotation.
Applications & Selection
How the vulcanized bond carries the load
A molded-on rubber wheel is a bond-owned assembly: the rubber tread takes the floor contact and the shock, but every braking, cornering and pushing force crosses the rubber-to-core interface. Vulcanization — rubber cured onto a prepared core under heat and pressure — creates a chemical-mechanical bond far stronger than adhesive bonding, which is why published manufacturer construction statements lead with it. The failure mode to manage is bond degradation from heat, oil or abuse; a lifted or separated tread edge is a replacement flag, not a running condition.
Core choice is the second decision. Cast iron cores (published at 90-95 Shore A hard tread up to 2,500 lb, or softer 70-85 Shore A treads on larger 12-16 in wheels to 2,570 lb) put a rigid, precision-bored hub under the rubber; die-cast aluminum cores (published 250-600 lb at 4-8 in, 80-83 Shore A) trade capacity for weight — meaningful on manually handled carts. Pick by capacity, weight and bore/bearing needs, not by which line sounds premium.
Our supply path is own production plus outsourcing. Bands above are manufacturer references for class positioning; your per-configuration rating is confirmed at quotation.
Floors, static loads and the boundaries of the rubber-on-core answer
The published case for the construction is floor-and-noise economics: combining a rubber cover with a cast iron or steel body puts the durability of the metal load path together with the cushioning and noise insulation of rubber, and soft-tread selection charts place rubber among the maximum-floor-protection, quiet-running choices — steel and cast iron alone are explicitly not recommended where floor protection matters. On rough outdoor surfaces the same guidance carries a caveat that matters for this class: rougher surfaces accelerate wear on softer compounds, so a firmer tread compound (the 90-95 Shore A lines rather than the softest grades) is the usual outdoor rubber answer.
Static loads are the failure mode this class shares with all rubber. Industry flat-spot guidance is explicit that rubber compounds cold-flow under continuous static load — a wheel parked loaded above roughly 60% of its rated capacity for extended hours deforms plastically and flat-spots, and the iron or aluminum core does not save it because the deformation is in the tread. For carts and racks that stand loaded for days, the published fixes are rotating parking positions, lifting loads off the wheels, or moving the tread to polyurethane; for the rubber construction, sizing the tread to comfortably under the dwell load is the design answer.
Two boundaries belong in every RFQ for this class. First, rubber treads are the temperature-limited element of the assembly — the core tolerates heat the compound does not, so state ambient and contact heat, not just load. Second, dynamic capacity is always lower than static: a mold-on wheel that holds a parked load without deforming is not automatically rated to roll that same load across thresholds and dock plates at speed. Quote both conditions and the per-configuration rating holds up in service.
Frequently Asked Questions
What is the difference between mold-on rubber and soft rubber wheels?
Construction and capacity shape. Mold-on wheels are rubber vulcanized onto a rigid core (cast iron or aluminum), so the hub, bore and load path come from the core and the published bands reach 2,500 lb class figures; the soft performance lines are rubber-heavy constructions specified for floor protection and noise at lighter bands. Choose mold-on when the wheel must carry more or needs a precision bore; choose soft-tread when floor contact is the whole job.
Which core should I specify — cast iron or aluminum?
Published line bands put cast-iron-core wheels at 340-2,500 lb and aluminum-core wheels at 250-600 lb. Specify cast iron for heavier duty and precision bores; aluminum where wheel weight matters for manual handling. Both share the same vulcanized-bond ride character.
What should my mold-on rubber wheel RFQ include?
Load per wheel and duty cycle, speed, floor conditions, temperature at the wheel (rubber is the temperature-limited element), diameter and tread width, core material and bore, bearing type, and quantity. Ask how the tread is bonded to the core and how bond integrity is inspected — the bond is the assembly.
Ordering & Documentation
Documents
Every order ships with a packing list and commercial invoice. Dimensional drawings (diameter, tread width, bore, hub length) are available on request; the compound durometer and core material for the batch are stated on the quotation.
Quotation
A quotation needs: load per wheel and duty cycle, temperature, diameter and tread width, core and bore, bearing type, and quantity. The confirmed quotation states the rating for your configuration — published line bands are references, the quotation is the commitment.
Sample & supply
Standard constructions are produced to order with an MOQ of 200 pieces; smaller trial quantities of catalog items can ship in some sizes — ask with your RFQ. Lead time is 15-20 days standard, 30-40 days for custom cores or compounds.
Storage & shipping
Store away from sunlight, ozone and heat sources; rotate stock. Before installation, inspect the tread-to-core bond line — any lift, blister or separation is flagged and replaced before the wheel enters service.