Quick Answer
A pultrusion die (heated mold) defines the final cross-section of a pultruded FRP profile. IncomePultrusion engineers and machines custom dies in tool steel—with chrome or nitride surface treatments—for tubes, channels, I-beams, and bespoke sections, with cavity drawings, shrinkage allowance, and B2B lead times quoted per profile. Dies ship standalone or bundled with creel racks and production lines.
- Typical materials: P20 tool steel, chrome-plated cavities, hardened wear zones for high-output lines
- Engineering deliverables: 2D/3D cavity drawings, heating layout, and tolerance targets aligned to your resin system
- Supply model: standalone die orders or dies bundled with new pultrusion machines; MOQ depends on profile complexity
Custom Pultrusion Dies & Heated Molds
IncomePultrusion engineers and machines custom pultrusion dies (heated molds) for FRP profile production. We build tool-steel cavities with chrome or nitride surface treatments, supply cavity drawings with shrinkage allowance, and quote B2B lead times per cross-section.
- Materials: P20 tool steel, hardened wear zones, polished release surfaces
- Engineering: 2D/3D cavity layouts, heating zones, and tolerance targets aligned to your resin system
- Supply model: standalone die orders or dies bundled with new pultrusion machines
Read the full pultrusion mold design guide for engineering depth.
How To Machining And Design The Pultrusion Die?
After confirming the drawing, IncomePultrusion will cut the material with space.
Change the precision CNC center to 0.1mm feed at high cutting speed.
Use the “mm” Unit High Grinding to narrow drawing tolerances.
Polish the surface with your hand and machine the closed surface.
What steel material could be a choice for a pultrusion die?
Pultrusion molds can be made from various materials. Common ones include P20, 38CrMoAl, Cr12, 40Cr, and H13. Their hardness levels generally range from HRC55 to HRC65. Techniques like nitriding, chromizing, quenching, and polishing can improve molds. They can boost performance and durability. Molds can have a single or many cavities, depending on the product’s requirements. Their service life, 50,000 to 200,000 meters, depends on the mold’s design, material, and maintenance. These factors determine the mold’s efficiency and the product’s quality. They are critical in pultrusion manufacturing and cannot be overlooked.
P20 STEELP20 steel is a pre-hardened plastic die steel. It has good machinability, better polishability, and is easy to texture. It is widely used for injection molds and extrusion dies. It has excellent wear resistance, high compressive strength, and toughness. Also, it has very low shrinkage during heat treatment. This makes it ideal for intricate parts with tight tolerances. This steel has high corrosion resistance in humid areas. It also welds well using proper techniques. In pultrusion technology, P20 is highly ductile. So, it can be easily machined into complex shapes.
H13 MaterialH13 is the ability to keep hardness and strength at elevated temperatures. H13 steel has heat and corrosion resistance. So, it is ideal for pultrusion technology that needs protection from corrosive chemicals. Also, H13 steel has excellent forging characteristics. This allows for faster production rates than with conventional steels.
So we usually choose this material to increase the faster delivery time.
12Cr-Mo-V STEEL12Cr-Mo-V is that it has a high tensile strength and good corrosion resistance. This makes it ideal for applications for epoxy system pultrusion. It can operate at elevated temperatures up to 500°C without any changes to its properties. Also, the steel contains molybdenum. It increases creep strength and fatigue life. It also reduces wear from abrasive agents. The composition also includes chromium. It improves oxidation resistance. So, 12Cr-Mo-V steel can be used in harsh conditions where other steels would not last. These elements make the alloy very durable over time. So, it is a great choice for many industrial uses where reliability is crucial.
Key Considerations in Pultrusion Die Design
Different resins have different curing times and viscosities. These affect how the material flows through the die.
The die must match the desired final product shape. It must also hold the volume of resin and fibers. Adequate clearance is necessary to ensure smooth flow without causing defects.
Proper cooling is essential. It allows the resin and fibers to cure as they are pulled through the heated die. The cooling system must efficiently cool the entire cross-section of the product.
For some simple products, we will design multi-cavity molds to meet customer needs.
Preformer
In pultrusion molding, the reinforcing material must be impregnated with resin. Then, it must pass through a preform mold made of yarn guiding elements. After that, it can enter the forming mold. The preform mold removes excess resin and bubbles from the impregnated material. It also shapes the material to match the mold cavity before it enters the mold. The performance of the reinforcing material will shape it. Its cross-section must meet design requirements.
Customzied Pultrusion Mandrel
The mandrel is key in making hollow profiles or tubes. In the pultrusion process, thick-walled products may use heating rods inside the mandrel. They cure the resin. We select P20 material as the ideal choice for mandrels. It is pre-stressed, easy to polish, and has other good properties.
The mandrel’s length is usually 600 mm to 700 mm longer than the mold. It depends on the needs of the performing process. For processes with many felt layers, the mandrel can be 2500 mm to 3000 mm long. This length is needed to evenly heat the profile during pultrusion. It will cure and merge the resin.
Pultrusion mold design guide — case references
Pultrusion Die Types We Supply
IncomePultrusion builds custom pultrusion dies for FRP profile production. Every tool is machined to the buyer’s drawing and can be ordered as a standalone die or bundled with a complete pultrusion line, including the machine, creel and downstream handling equipment. The pultrusion die types below cover the cross-sections that B2B buyers order most often, and sections outside them are quoted as custom tools through the same drawing-led process.
| Die type | Profile family | Link |
|---|---|---|
| H-shape / I-profile die | Structural beams and columns for construction profiles | View product page |
| C-channel & ladder rail die | Channels, angles and ladder rail sections | View product page |
| Handrail die | Round and square handrail and guardrail sections | View product page |
| Seamless tube die + mandrel | Hollow round and square tubes | View product page |
| Custom profile dies | Buyer-drawn cross-sections of any complexity | Quoted from your drawing |
All five of these pultrusion die types are families tooled from buyer drawings rather than variants pulled from a stock catalog, and every quotation starts from the profile cross-section. The drawing determines the cavity arrangement, whether a mandrel is required for hollow sections, and which heating configuration suits the resin system you intend to run. Send the section you want to produce and the quotation is built around it; we do not ask buyers to compromise a profile so that it fits a tool already sitting on a shelf.
Ordering works in both directions. A standalone die is delivered ready to mount on your existing line, with mounting interfaces and heating connections confirmed at RFQ so that installation does not turn into reverse-engineering on your shop floor. Ordered as part of a machine and creel package, the die is matched to the line’s pull force, heating capacity and cut-off arrangement before it ships, so commissioning starts from a proven combination rather than a first-time pairing of tool and equipment. Buyers who already run one line often start with a standalone tool and move to bundled orders once a profile family is proven; both routes are routine for us.
What a Pultrusion Die Quote Includes
A quotation for a pultrusion die is an engineering commitment, and it is worth knowing what a supplier is actually pricing before comparing offers. Beyond the steel itself, a complete quote covers the heating configuration, the working length of the cavity, the finish applied to the cavity surface, and any internal tooling needed for hollow sections. Knowing where each published figure comes from also tells you which questions to ask when two quotations differ. The table below lists those elements with the typical specifications reported across the industry, alongside the caveats that apply to each. Where a figure varies between sources, the note column says so rather than presenting a single value as universal.
| Element | Typical specification | Note |
|---|---|---|
| Die steel | Tool steel; P20 widely specified for pultrusion cavities | Why P20 is used in pultrusion mold manufacturing |
| Heating zones | 2–8 zones standard; up to 24 zones optional | Equipment-level specification, cited from Pultrex machine ranges |
| Working length | Around 1,000 mm reported for profile dies | Reported in academic literature; set per profile |
| Cavity finish | Hard chrome plated | No published standard thickness — confirmed at RFQ |
| Hollow profiles | Mandrel with internal heating rods for thick-walled sections | Standard configuration for seamless tube dies |
| Die temperature control | 80–100 °C reported | Reported in pultrusion studies — resin-specific setpoints vary |
To receive a quotation built on requirements rather than assumptions, send four things with your RFQ. First, the profile cross-section drawing, which drives the cavity arrangement and any internal tooling. Second, the resin system you will run, including fillers, because chemistry and abrasiveness influence both the steel specification and the cavity finish. Third, your target annual volume, which determines whether a single-cavity or a multi-cavity tool is the economic answer. Fourth, state whether the die is a standalone purchase or bundled with a machine line, because that changes what we check and what we commit to. With those inputs, the quotation you receive is a buildable document rather than a rough estimate.
Die or Mold? One Tooling, Two Names
In pultrusion, “die” and “mold” name the same tool: the heated cavity through which resin-impregnated fibers are pulled and cured. Neither term is wrong, and neither signals a different manufacturing route. Usage is regional. American specifications and purchase orders say “die”, while “pultrusion mold” is the more common term in other varieties of English, and buyers meet both on datasheets, drawings and quotations. When comparing suppliers, treat a quote for a die and a quote for a mold as the same scope of work, and compare the tooling elements rather than the label. For the engineering behind the tool — cavity layout, steel selection rationale and machining sequence — see our two guides: pultrusion mold design and manufacturing and pultrusion mold design requirements.
Maintenance & Refurbishment
A die is a long-service tool rather than a consumable, but it does wear. One industry estimate places major rework at approximately 50,000 m of production. Treat that figure as a reference point rather than a guarantee: actual service life depends on how abrasive the resin formulation is, whether it carries mineral fillers, and how carefully the cavity is handled between production campaigns. Abrasive fillers are the main driver of cavity wear, because every meter of output drags loaded material across the same steel surface. Filled and gritty formulations therefore shorten the interval between refurbishments, while a clean resin system, stable heating and disciplined handling between campaigns extend it.
Refurbishment works best as a scheduled program rather than a breakdown response. In practice that means periodic cavity inspection, checks on the condition of the hard chrome, and re-polishing and re-chroming at refurbishment once the surface has degraded beyond what polishing alone can recover. It also means alignment checks against the pultrusion machine line, because a die that does not track true through the pull wears unevenly and transfers that wear straight to the profile. Refurbishment is quoted per die condition after inspection: a lightly worn cavity needs far less work than one that has lost its chrome, and the quotation covers only the work the tool actually needs.
Pultrusion Die FAQ
What is the difference between a pultrusion die and a mold?
No difference in hardware. They are two names for the same heated, shaped tool through which the profile is pulled and cured. “Die” is standard in American usage and “mold” is more common elsewhere, so both terms appear in specifications, datasheets and quotations from different suppliers. Compare offers on tooling scope rather than terminology, and check that both parties mean the same component. If a quotation uses one term and your drawing uses the other, ask the supplier to confirm the scope in writing. For the engineering side of the tool, see our guide to pultrusion mold design and manufacturing.
How many heating zones does a pultrusion die need?
Mainstream machines carry 2–8 heating zones as standard, with up to 24 zones optional on larger lines. The right count for a given tool depends on the profile cross-section, the wall thickness being cured and how the resin system behaves during cure, so the number is fixed at quotation rather than assumed at the inquiry stage. A thin, simple section rarely needs the largest available configuration; a thick-walled, complex one usually does. Send the section and the resin with your inquiry, and the heating configuration is specified alongside the price.
What is the lead time for a custom pultrusion die?
There is no single published lead time for a tool of this kind, and any figure offered before the drawing has been reviewed is a guess. Duration depends on profile complexity, cavity count and surface treatment, and it is confirmed only after engineering review of the cross-section. Request a quote with your profile drawing and we will return a schedule alongside the price.