Custom Cast Polyurethane Parts

What is a cast polyurethane part?

A cast polyurethane part is an industrial component made by pouring a liquid formulation into a mold, then controlling its polymerization and its cure.

It sits between an elastomer and a rigid plastic: we adjust the chemistry and the hardness to cover the whole range, from very soft to Shore D. Properly formulated, it takes abrasion, load and impact where rubber wears out too fast and plastic breaks.

Pièce moulée en polyuréthane double dureté usée et décollée, en fin de vie — 1. La pièce double dureté arrive usée et décollée

Pièces en polyuréthane coulées dans leurs moules d'acier, en cuisson contrôlée au four — polyuréthane coulé à chaud — 2. Coulée dans nos moules, cuisson contrôlée au four

Pièces moulées en polyuréthane rouge double dureté finies sur cœur d'acier, adhérisation validée — 3. Pièces double dureté remoulées, prêtes à livrer

Notre procédé — coulé à chaud & surmoulage+

Soremag casts polyurethane

hot

(

hot cast

) for higher mechanical and dynamic properties, using a casting method

matched to the part

(process chosen according to the shape and the concentricity). The polyurethane can be

overmolded directly onto a metal insert

(steel, stainless, aluminum) with a validated bonding system — a rigid skeleton and a PU working surface in a single part.

Nos équipements de moulage+

We cast with

advanced automatic casting machines

: an

automatic StateMix meter-mix dispenser

fitted with every option, backed by

several StateMix Vortex mixers

. Metering and mixing of the components are

machine-controlled, to a high degree of precision

— every formulation is cast at the exact ratio, which makes it possible to reach the

maximum properties

of the recipe, cast after cast. Add to that molds designed and built in-house, controlled cure and post-cure, plus

precision machining

and

laboratory inspection

(hardness, dimensions, adhesion).

Notre savoir-faire+

Molding polyurethane is a

demanding chemistry

: we calculate every parameter of every pour —

NCO content

, curative stoichiometry,

temperatures

of the components, the mold and the cure, gel time and demold time — to

leave nothing to chance

. That strict control of the chemistry and the process, combined with the precision of our equipment, is what guarantees that every part delivers the properties its formulation calls for.

Notre adaptation à vos besoins+

We work with your reality:

one-off part, prototype, short run or recurring production

. We work from a drawing, a 2D/3D file, a sketch or an

existing part — even a worn one

(reverse engineering). And we don't just copy: we look for

why

the part wears or breaks, then we adjust the material, the hardness, the geometry or the mounting so it lasts longer. Shape, hardness, color, metal insert, quantity: everything is set to suit your application.

Moulé, usiné ou injecté : quelle différence ?+

Molded (cast)

: a liquid thermoset formulation is poured and then cured — maximum mechanical properties, free shapes, no heavy tooling.

Machined

: cut from an existing block, limited by the stock sizes available.

Injection molded

: molten thermoplastic forced under pressure into an expensive mold — cost-effective in very high volumes, with generally lower properties. For industrial custom work, from prototype to production run,

cast polyurethane

is most often the best option.

Give us the function, the load, the environment and the target hardness — or simply a worn part to copy — and we select the formulation and the casting process that fit best — in Quebec, across Canada and in the United States.

Get a custom analysis

The parts we cast, by family

An overview of what we mold in polyurethane. The list is not exhaustive: if your part takes wear, load or impact, it can probably be cast in polyurethane.

Wear and material handling

Wear parts & liners (liners, wear pads)

Linings for chutes, hoppers and transfer points where material slides and strikes. Polyurethane can outlast some steels and rubbers depending on the wear mode (abrasion, impact, corrosion) — and it is lighter and modular. View the page →

Ceramic + PU wear parts (bead bar)

We embed ceramic beads or tiles in a polyurethane matrix: the PU absorbs the impact and holds the ceramic, which takes the sliding abrasion. Especially effective where the application combines sliding abrasion and impact (mining, bulk material handling). View the page →

Scrapers, lips & wiper blades (scrapers / belt cleaners)

Flexible blades that scrape a conveyor belt or clean a surface. Polyurethane holds its edge longer than rubber, and it does not corrode. View the page →

Pièces d'usure en polyuréthane sur fond blanc

Screen panels & flexible screens (screen / flip-flop)

Modular vibrating screen panels for sizing and dewatering (mining, quarries). Polyurethane lasts far longer than steel wire mesh, reduces blinding and is replaced module by module.

Motion and power transmission

Pièces de mouvement et transmission en polyuréthane sur fond blanc

Bushings, sleeves & bearings (bushings)

Sleeves that act as a bearing or as an interface between two moving parts, replacing bronze or rubber. Polyurethane cushions, resists wear and does not corrode, without galling. View the page →

Gears, sprockets & toothed wheels (gears)

Cast gears and sprockets, often on a metal core. Polyurethane runs more quietly, absorbs shock and avoids metal tooling — practical for large diameters. View the page →

Couplings & spiders (coupling spiders)

The elastomer element (the “spider” in a jaw coupling) that transmits torque while absorbing misalignment and shock. The resilience of polyurethane takes more than rubber does. View the page →

Impact, sealing and vibration

Bumpers, pads & shock absorbers (bumpers)

Blocks and pads that absorb impact and cushion stops. Polyurethane takes the hit, then returns to shape while cutting noise, vibration and damage. View the page →

Seals, sealing rings & V-rings (seals / U-cups)

Molded sealing elements (seals, U-cups, V-rings) to contain a fluid or keep contaminants out. The high mechanical strength of polyurethane extends the life of hydraulic and dynamic seals. View the page →

Vibration isolators & mounts

Molded vibration isolators, pads and mounts that decouple equipment and protect structures — durable even under load and in wet or oily environments.

Pièces anti-chocs et d'étanchéité en polyuréthane sur fond blanc

Special engineered parts

Pièces techniques spéciales en polyuréthane sur fond blanc

Parts overmolded on metal (overmolding)

Polyurethane cast onto an insert or a core made of steel, stainless steel or aluminum : the part combines a rigid skeleton and a PU working surface. Ideal for pump liners, wheels and drive belts. View the page →

Pump, turbine & hydroelectric parts

Liners, bushings, seals and wear parts for slurry pumps and hydraulic equipment — and large cast parts for turbine and hydroelectric applications, where abrasion and erosion do the damage.

Plates, bars & machining stock

Plates, bars and cylinders in polyurethane, cast to the hardness you need, ready to be turned, milled or cut — the base material for custom parts machined on site.

A specific part in mind, or a sample to copy? Tell us about your part →

How far we can go in cast polyurethane

The real numbers from our shop: hardness, dimensions, weight, tolerances and finish.

Hardness

From

10 Shore A

(very soft) to

85 Shore D

(rigid) — recipes under continuous improvement.

Part weight

From

less than 1 gram to more than 2,500 lb

(≈ 1,135 kg) — no fixed maximum.

Dimensions

From

2 mm

up to

20 ft. long

(≈ 6 m) — machining up to

Ø 42 in. × 240 in.

Ø 68 in. × 175 in.

Ø 76 in. × 36 in.

, lifting up to

10 metric tons

(22,000 lb).

Metal inserts

Any metal — steel, stainless steel, aluminum and others — depending on the part.

Finishing & machining

Turning, grinding, cutting, drilling, grooving and profiling.

Tolerances

After molding:

less than 2%

. After machining or grinding: down to

±0.001 in. (±0.025 mm)

depending on the compound.

Polyurethane foam

We also cast parts in

polyurethane foam

(cellular systems) for cushioning, sealing and weight reduction.

Colors

Every color available, depending on the formulation and the application.

Advantages of hot cast polyurethane

Why choose hot cast polyurethane?

Hot cast polyurethane produces engineered parts that combine wear resistance, resilience, load capacity and dimensional stability. The formulation, the hardness and the cure cycle can be matched to the actual service conditions: abrasion, impact, moisture, oils or dynamic loading.

The result: longer-lasting custom parts, made with or without a metal insert.

Plaque d'usure en polyuréthane rouge coulé à chaud résistant à l'abrasion, projections de roche — Soremag Québec

Wear
and abrasion resistance

Engineered formulations built to resist abrasion, cutting and wear in demanding environments.

Idéal pour plaques d'usure, racleurs et pièces soumises à l'abrasion.

Rouleau en polyuréthane ambre naturel comprimé entre deux plateaux d'acier

Load, impact
and resilience

The material absorbs impact, returns to shape and carries repeated loads with excellent mechanical durability.

Adapté aux roues, rouleaux, butées et applications dynamiques.

Pièce surmoulée : insert d'acier usiné dans un bloc de polyuréthane jaune, coupe montrant la liaison par adhérisation

Overmolding
that lasts on metal

Polyurethane can be cast onto a metal core or insert to combine rigidity, adhesion and wear resistance.

Une seule pièce intégrée, fiable et robuste.

Pièces en polyuréthane sur mesure et moules d'atelier (une et vingt cavités)

Manufacturing
parts

From prototype to small or medium production runs, the process turns out simple or complex parts with optimized tooling.

Formulation, dureté, dimensions et inserts adaptés à l'application.

Les bénéfices clés pour vos opérations

Less downtime

Longer service life and fewer unplanned replacements.

Better efficiency

Less maintenance, more uptime.

Lower total cost

A durable solution that protects your budgets over the long term.

Less noise and vibration

Smoother running and better operating comfort.

Hot cast polyurethane: up to 5× more resistant to wear and tearing than some rubbers.

Which polyurethane formulation should you choose?

Hardness is a starting point, not a formulation — we choose based on what the part actually does and the conditions it runs in.

A cast polyurethane formulation combines several elements: the

isocyanate family

(TDI, MDI, NDI, PPDI or another system), the

polyol family

(polyester, polyether, polycaprolactone…), the curative system, the component ratio, the additives, the cure cycle, the geometry and the thickness. At

the same hardness

, two parts at 90 Shore A can behave completely differently in abrasion, tear, load capacity, rebound, compression set, heat build-up, resistance to water and oils, or dynamic behavior.

Contrainte dominante	Propriétés prioritaires	Orientation technique à évaluer
Abrasion (glissement, particules, impacts)	Abrasion, coupure, déchirure, résilience	Polyester haute performance ; céramique noyée si abrasion + impacts
Eau, humidité, vapeur	Résistance à l'hydrolyse	Système polyéther ou polyester stabilisé
Charge dynamique, vitesse, cycles	Faible hystérésis, tenue en fatigue	Système dynamique TDI, MDI, NDI ou PPDI selon charge et fréquence
Huiles, produits chimiques	Compatibilité chimique ciblée	Formulation choisie après identification du fluide et de la température
Températures extrêmes (froid ou chaud)	Flexibilité ou stabilité thermique	Polyéther/MDI au froid ; formulation validée en température, parfois NDI ou PPDI, au chaud
Contact alimentaire, antistatique	Conformité documentée, résistivité contrôlée	Formulation FDA documentable ou antistatique/conductrice validée

General guidance, not prescriptions: the final formulation is validated against the part, the geometry, the environment, the load and the target result.

Full guide:

detailed selection matrix (20 stresses), abrasion, hydrolysis, hysteresis, oils and chemicals, ceramic, what Shore hardness does not tell you, and our 6-step selection method.

Read the full guide →Tell us about your part

Pourquoi Soremag

Polyurethane expertise, from the recipe to the finished part

For more than

35 years

, Soremag has formulated and cast polyurethane for the

largest manufacturing companies

in Quebec and beyond. What sets us apart is that we control

every step in-house, with no subcontracting

— from the chemistry through to machining the part.

Technicien Soremag coulant du polyuréthane liquide rouge dans un bécher gradué depuis un dispenseur automatique StateMix — Dosage et mélange automatiques StateMix — la précision machine au service de la formulation.

Our molded-part know-how, A to Z

Formulation de recettes à l'interne — polyols (polyester, polyéther, polycaprolactone) et isocyanates (TDI, MDI, NDI, PPDI) ; duretés du souple au Shore D.
Coulée à chaud (hot cast) — dégazage, dosage et contrôle thermique pour limiter bulles, défauts internes et variations dimensionnelles.
Coulée adaptée à la pièce — méthode choisie selon la forme et la concentricité (procédés spécialisés selon le projet).
Surmoulage & adhérisation sur métal — acier, inox, aluminium ; préparation et système d'adhérisation adaptés au métal, aux efforts et au service.
Usinage de précision — tournage, meulage et découpe pour les tolérances et les finitions.
Grandes pièces & petits lots — de la bague à la pièce lourde, sans outillage métallique coûteux.
Formulations spéciales (selon projet) — contact alimentaire, antistatique/conducteur, chargée céramique, faible hystérésis.
Reverse engineering — reproduction d'une pièce sans plan, à partir d'un échantillon.
Validation en laboratoire — dureté Shore A/D, adhésion, contrôle dimensionnel.
Plan de contrôle selon la fonction — vérifications définies selon les caractéristiques critiques et le risque de la pièce (démarche qualité QC7).

See our quality control (QC7) →

Questions about cast polyurethane parts

Coussinets de pont élévateur en polyuréthane rouge, noir et jaune à surface pyramidale

Automobile

Pads for automotive vehicle lifts

Molded polyurethane lift pads — round, rectangular, textured or custom. The durable alternative to rubber pads for dealerships, garages and repair shops.

Voir la page →

Why molded polyurethane instead of rubber or plastic? +

Cast polyurethane combines the flexibility of rubber with the strength of a plastic. Depending on the application, the right formulation can offer abrasion and cut resistance well above rubber, high load capacity, good rebound and good resistance to many oils — the real gain is confirmed by testing or by operating data. We mold it from soft (Shore A) to rigid (Shore D), in the shape you need, with no expensive metal tooling.

Can you mold polyurethane directly onto a metal part? +

Yes. The polyurethane is cast and overmolded onto a steel, stainless or aluminum insert or core, with validated surface preparation and bonding system. You get a part that combines a rigid metal skeleton with a PU working surface — tough, quiet and wear-resistant.

Do you make parts when there is no original drawing? +

Yes. Through reverse engineering, we reproduce a part from a sample, a worn part or a sketch, even with no drawing — dimensions, hardness and material included.

How large a part can you cast? +

From a small bushing a few millimeters across to large, heavy parts for pumps, mining screens and hydraulic or turbine equipment. Casting makes it possible to produce large parts that are difficult or expensive to machine from metal.

Do you make ceramic and polyurethane wear parts? +

Yes. We mold wear parts that combine ceramic beads or tiles with a polyurethane matrix (“bead bar” type) for the most abrasive environments: the PU absorbs the impact, the ceramic takes the sliding abrasion.

What is the minimum order quantity? +

There is no minimum: a single part is cast just as readily as a production run. Because the molds are built in-house and casting does not require expensive metal tooling, the one-off prototype, the urgent replacement part and recurring production are all economically viable.

Which polyurethane hardness should I choose for my part? +

The range runs from about 10 Shore A (very soft, cushioning) to 85 Shore D (nearly rigid). The right choice depends on the job: absorbing impact, carrying a load, resisting abrasion, scraping or guiding. We select the hardness and the formulation with you based on the actual conditions — an existing part can serve as a starting point to characterize.

Does polyurethane resist oils and chemicals? +

In general, good resistance to many oils, greases and aliphatic solvents — often better than that of most rubbers. The exact resistance depends on the chemical family (polyester, polyether, polycaprolactone) and on the medium: hot water, steam and certain chemicals call for an appropriate formulation. We validate chemical compatibility before casting.

Can you improve on the original part instead of simply copying it? +

Yes, and that is often the real value of custom molding: if the original part wears out too fast, tears or deforms, we adjust the hardness, the formulation or the geometry to correct the failure mode observed. Reproduce, but also improve — especially when the original part was not lasting.

What are your lead times? +

Everything is done in-house — molds, casting, finish machining — which shortens lead times compared with a subcontracted chain. The actual lead time depends on the complexity of the part and on whether a mold is available. For a critical breakdown, our 24/7 emergency service lets us handle the part as a priority.

Custom cast polyurethane parts

What is a cast polyurethane part?

A part for every industrial function

The parts we cast, by family

Wear and material handling

Wear parts & liners (liners, wear pads)

Ceramic + PU wear parts (bead bar)

Scrapers, lips & wiper blades (scrapers / belt cleaners)

Screen panels & flexible screens (screen / flip-flop)

Motion and power transmission

Bushings, sleeves & bearings (bushings)

Gears, sprockets & toothed wheels (gears)

Couplings & spiders (coupling spiders)

Impact, sealing and vibration

Bumpers, pads & shock absorbers (bumpers)

Seals, sealing rings & V-rings (seals / U-cups)

Vibration isolators & mounts

Special engineered parts

Parts overmolded on metal (overmolding)

Pump, turbine & hydroelectric parts

Plates, bars & machining stock

How far we can go in cast polyurethane

Hardness

Part weight

Dimensions

Metal inserts

Finishing & machining

Tolerances

Polyurethane foam

Colors

Why choose hot cast polyurethane?

Wearand abrasion resistance

Load, impactand resilience

Overmoldingthat lasts on metal

Manufacturingparts

Less downtime

Better efficiency

Lower total cost

Less noise and vibration

Which polyurethane formulation should you choose?

Polyurethane expertise, from the recipe to the finished part

Our molded-part know-how, A to Z

Industries served

Our cast polyurethane specialties

Wear plates & liners

Metal Overmolding

Bushings, plain bearings & sleeves

Scrapers, blades & wipers

Bumpers, stops & shock absorbers

Gears, sprockets & star wheels

Polyurethane wheels

Polyurethane Rollers

Other custom parts

Questions about cast polyurethane parts

Pads for automotive vehicle lifts

Why molded polyurethane instead of rubber or plastic? +

Can you mold polyurethane directly onto a metal part? +

Do you make parts when there is no original drawing? +

How large a part can you cast? +

Do you make ceramic and polyurethane wear parts? +

What is the minimum order quantity? +

Which polyurethane hardness should I choose for my part? +

Does polyurethane resist oils and chemicals? +

Can you improve on the original part instead of simply copying it? +

What are your lead times? +

A part to mold or to copy?

Wear
and abrasion resistance

Load, impact
and resilience

Overmolding
that lasts on metal

Manufacturing
parts