Product Catalog
Ductile Iron Caster Wheels — Tough Cast Metal Wheels Between Cast Iron and Forged Steel
Updated 2026-11
Ductile iron occupies the middle of the metal-wheel ladder. Industry material guides band the three cast-metal wheel sub-types on the same axes: cast iron carries 1,000-3,000 lb per 5-inch wheel but is impact-brittle; forged steel carries 2,000-10,000+ lb with excellent toughness at the highest cost; ductile iron sits between — 1,500-5,000 lb per 5-inch wheel, service to 600°F, and "tough" impact behavior at roughly 30-50% above cast iron cost. The same guides compress the selection rule into one line: spec forged for impact, cast for static, ductile iron for the middle.
The "tough" is the point. Ductile iron is cast iron with the graphite reformed into nodules, which bends the failure mode from sudden fracture toward deformation — the wheel dents and wears instead of cracking when a load lands hard. Manufacturer wheel lines carry it as a standard family (FM and FR series in one major line's catalog), which means ductile iron wheels can be specified as catalog items, not custom forgings. Our ductile iron line is quoted per application: diameter, bore, bearing and the rating for your configuration are confirmed at quotation.
Specifications
| Type | Ductile (nodular) cast iron caster wheels; swivel and rigid caster assemblies |
|---|---|
| Class load band (industry reference) | 1,500-5,000 lb per wheel at 5 in diameter (published material-class band — per-size, not a family rating) |
| Class temperature (industry reference) | -40°F to 600°F (published material-class band) |
| Impact behavior (industry reference) | Tough — deforms rather than fractures under impact (vs brittle cast iron, excellent forged steel) |
| Cost position (industry reference) | Approximately +30-50% over cast iron baseline; below forged steel |
| Manufacturer line structure | Standard catalog wheel family (e.g. FM / FR ductile iron series in published lines) |
| Tenant family rating | No published tenant family rating — capacity, bore and bearing per configuration confirmed at quotation |
| Lead time | 15–20 days (custom configurations 30–40 days) |
| MOQ | 200 pieces (standard catalog items ship in smaller quantities) |
| Warranty | 18 months |
All load, temperature and cost figures on this page are published industry-class or manufacturer-line reference values, quoted per size and never merged into one promise. The rating for your diameter, tread width and bearing is confirmed at quotation.
Applications & Selection
The problem ductile iron solves
Ordinary gray cast iron has a weakness baked into its microstructure: the graphite sits in flakes that act as internal crack starters. Load it statically, and gray iron is superb — cheap, stiff, dimensionally stable, indifferent to heat. Hit it, and a crack starts at a graphite flake and runs. Ductile iron treats the graphite so it forms as nodules instead of flakes, and the crack-starters become crack-stoppers: the same casting route produces a wheel that tolerates pallet-edge impacts, apron seams and dock plates that would chip or crack a gray iron wheel.
That makes ductile iron the honest answer for a specific band of duty: loads and temperatures past what polymer wheels carry, impact duty that makes gray iron a liability, and budgets that make forged steel hard to justify. A foundry cart running hot molds across a rough apron, a steel-mill transfer fixture, a heavy tooling dolly that gets dropped off loading dock plates — duty where the wheel sees 500°F and a hard life at the same time. Published class bands put that duty exactly in ductile iron's window: 1,500-5,000 lb at 5-inch diameter, service to 600°F, tough under impact.
The trade-offs are the metal-wheel trade-offs: ductile iron is hard on finished floors, loud, and transmits shock to the load — there is no tread compliance at all. On sealed or polished concrete, a polymer or elastomer tread is almost always the better answer, and the metal wheel belongs on steel plate, aprons and debris floors.
Selection points to settle before you RFQ
Place your duty on the three-metal ladder honestly. The published selection logic — forged for impact, cast for static, ductile for the middle — is a decision rule, not a slogan: if your loads are static machine-base weight on a smooth floor, gray cast iron is the economical answer; if the duty is tow-line impact at the heaviest ratings, forged steel pays for itself; the band in between — moderate impact, high temperature, mid-four-figure loads — is where ductile iron wins on total cost.
Then the hardware questions: diameter and tread width for your load (class bands are per-size — a 5-inch band does not extend downward), bore and bearing type (at 500°F-class temperatures, bearing and lubricant limits arrive before the iron's), and mount: swivel for maneuvering, rigid for straight-line heavy runs, or a swivel-and-rigid set. If the wheel runs in a V-groove or on track, say so — groove geometry is machined per track section.
Give the RFQ the abuse history as well as the load table: the worst impact event, the hottest zone and its dwell time, floor condition by segment of the route. Ductile iron is usually chosen because something in the route breaks lesser wheels — the quotation can only match that if the thing that breaks them is stated.
Frequently Asked Questions
Is ductile iron the same as cast iron for caster wheels?
Same family, different metallurgy, different failure mode. Both are cast-iron wheels, but gray cast iron has flake graphite that makes it brittle under impact, while ductile (nodular) iron has spheroid graphite that gives it "tough" behavior — it deforms rather than fractures. Published industry bands reflect it: cast iron 1,000-3,000 lb at 5 in with brittle toughness, ductile iron 1,500-5,000 lb at 5 in rated tough, at roughly 30-50% higher cost. If your loads get dropped or slammed, the difference is the wheel staying round.
When is ductile iron the right choice over forged steel?
When the duty fits its window. Forged steel carries the heaviest ratings (published bands: 2,000-10,000+ lb per 5 in wheel, -40..800°F, excellent impact toughness) but costs 150-250% over the cast iron baseline, against ductile iron's 30-50%. If your load and temperature sit inside ductile iron's band and the impact is "rough service" rather than sustained heavy tow-line shock, ductile iron delivers most of the toughness at a much lower price. The industry one-liner — spec forged for impact, cast for static, ductile iron for the middle — is a cost-optimized decision rule, and the middle is a wide band.
What should my ductile iron wheel RFQ include?
Wheel diameter and tread width, bore and bearing type (with the operating temperature the bearing will see — bearing lubricant usually limits service before the iron does), load per wheel, the worst impact event on the route, floor/track surface, mount type (swivel, rigid, or a set), finish requirement if the environment is corrosive, and quantity per size. State what broke the previous wheels — that one sentence usually determines the right spec.
Ordering & Documentation
Documents
Every order ships with a packing list and commercial invoice. Dimensional drawings (diameter, tread width, bore, hub) are available on request so your fixture designer can check fit before production, and the quoted rating for your size and bearing is stated on the quotation.
Quotation
A quotation needs: diameter, tread width, bore and bearing, load per wheel, temperature and impact history, mount type and quantity. The confirmed quotation states the capacity for your configuration — the published class bands above are industry reference values for placement, not the order commitment.
Sample & supply
Standard sizes are produced to order with an MOQ of 200 pieces; smaller trial quantities of catalog sizes can ship in some diameters — ask with your RFQ. Lead time is 15–20 days for standard configurations and 30–40 days for custom bores, bearings or groove work. A trial set on the worst segment of the route — not the easiest — is the usual validation.
Storage & shipping
Ductile iron wheels ship unprotected surfaces-down in cartons and store indefinitely in dry conditions; surface rust on a stored wheel is cosmetic and cleans off, but keep the bearing bores plugged. Before installation, inspect the tread for transport chips and spin each wheel — any wheel that took a hard hit in transit is flagged and replaced, because the point of choosing ductile iron is controlled behavior under impact, and you want that behavior to start from an undamaged wheel.