Jaw plates, cone crusher liners, blow bars, and hammers are among the highest-wear components on a mining crushing line — and among the most frequently replaced. The alloy used, the casting process, the quality of heat treatment, and any internal casting defects all have a direct impact on a wear part’s service life, the crusher’s throughput, and how often the line experiences unplanned downtime.
Today, wear parts for mining crushers are produced almost exclusively by casting. Different casting processes deliver noticeably different results in dimensional accuracy, internal soundness, production cost, wear resistance, and impact resistance. The three processes used most often are sand casting, lost foam casting (EPC), and bimetallic composite casting.
For high-manganese-steel wear parts, water toughening heat treatment is a critical step that determines microstructure and toughness. Shrinkage cavities, shrinkage porosity, gas porosity, sand inclusion, hot cracking, and failed heat treatment can all cause a wear part to fail prematurely.
This article walks through casting principles, the production workflow, material selection, a process comparison, common casting defects, quality testing, and purchasing guidance — covering how crusher wear parts are actually made, and how mining procurement teams can judge wear-part quality.
While a crusher is running, its jaw plates, liners, blow bars, and hammers are under constant impact, compression, friction, and wear from the rock being processed. At the same time, these parts tend to share several traits: large size, complex geometry, extensive curved surfaces, significant variation in wall thickness, and a high alloy content for wear resistance. Casting has become the dominant manufacturing method for mining wear parts largely because of these characteristics.
Different crusher types call for different wear-casting structures and performance requirements.
For jaw crushers, the main cast wear parts are: fixed jaw plate, movable jaw plate, and cheek plates. The jaw plate is a classic high-manganese-steel wear casting.
For cone crushers, the main cast wear parts are: mantle, concave, bowl liner, and crushing wall. These liners typically have complex curved geometries and demanding requirements for both dimensional accuracy and wear resistance.
For impact crushers, the main wear castings are: blow bars, impact plates, and liners. Blow bars have to withstand both high-speed impact and continuous wear.
For hammer crushers, common cast components include: hammers, screen plates, liners, and fine-crushing components. Hammers and liners in fine-crushing equipment are also typically wear castings.
Casting isn’t the only manufacturing method for crusher wear parts, but it holds a clear advantage for parts that are complex and large. Because casting can directly form intricate part geometries, it’s particularly well suited to: large jaw plates, cone crusher liners, wear parts with complex curved surfaces, thick-walled castings, high-manganese-steel castings, and high-chromium cast iron parts. Casting also allows manufacturers to achieve different combinations of hardness, toughness, and wear resistance by adjusting alloy composition and heat treatment.
Forging changes a metal’s shape and internal structure through plastic deformation, and it’s well suited to parts that are relatively simple in structure but demand high density and strong mechanical properties. For large crusher liners with complex curved surfaces, however, forging is generally more difficult and more costly to execute. In other words, it isn’t accurate to say “casting is always better than forging” — different parts call for different manufacturing processes. For large, complex mining wear parts, casting is generally easier to scale up for production.
A wear part’s final performance depends not just on the casting method, but also closely on the alloy material and heat treatment process used.
High-manganese steel is a common wear material for jaw crusher jaw plates and some cone crusher liners. Its defining characteristic is work hardening under strong impact and compressive loading — the working surface of the material gradually hardens as it absorbs impact, which improves wear resistance over time. As a result, high-manganese steel is particularly well suited to crushing applications with high impact loads.
High-chromium cast iron offers high hardness and good wear resistance. It’s commonly used for impact crusher blow bars, hammers, and some high-wear liners. That said, higher hardness doesn’t automatically mean better impact resistance — under high-impact conditions, hardness and toughness need to be weighed together.
The core idea behind bimetallic composite casting is straightforward: use a highly wear-resistant material in the working zone and a high-toughness material in the base. Combining two different materials this way lets the part balance wear resistance and impact resistance to a meaningful degree. This makes bimetallic composite castings particularly well suited to applications that demand both a long wear life and resistance to strong impact loads.
The casting methods most commonly used for mining crusher wear parts today are sand casting, lost foam (EPC) casting, and bimetallic composite casting. None of the three is unconditionally “the best” — the right choice depends on product structure, material, production volume, and actual operating conditions.
|
Comparison |
Sand Casting |
Lost Foam (EPC) Casting |
Bimetallic Composite Casting |
|
Process maturity |
High |
Relatively high |
Relatively high |
|
Large castings |
★★★★★ |
★★★ |
★★★★ |
|
Complex geometry |
★★★★ |
★★★★★ |
★★★★ |
|
Dimensional accuracy |
★★★ |
★★★★ |
★★★★ |
|
Batch production |
★★★★ |
★★★★★ |
★★★ |
|
Wear resistance |
Depends on material |
Depends on material |
Relatively high |
|
Impact resistance |
Depends on material |
Depends on material |
Relatively high |
|
Process difficulty |
Moderate |
Moderate |
High |
|
Overall cost |
Relatively controllable |
Clear advantage at volume |
Generally higher |
What ultimately determines wear-part quality isn’t the casting method itself — it’s whether material selection, melting, pouring, cooling, heat treatment, and quality inspection are all effectively controlled.
Sand casting is one of the more traditional and mature processes used to manufacture crusher wear parts.
The basic workflow is: mold making → core making → mold assembly → melting → pouring → cooling → shakeout → cleaning → heat treatment → machining → inspection.
Sand molds are typically made using materials such as resin sand or sodium silicate sand. In sand casting, molten metal is poured into the sand mold and allowed to cool and solidify into the desired casting.
Sand casting is particularly well suited to large jaw plates, cone crusher liners, large wear liners, and thick-walled high-manganese-steel castings. It offers strong adaptability for larger mining wear parts.
If mold making, coating, pouring, and venting aren’t properly controlled, the result can include gas porosity, sand inclusion, sand sticking, surface defects, and dimensional deviation. Sand castings also typically require more extensive cleanup and grinding after casting.
Lost foam casting, also known as EPC (Expendable Pattern Casting / Expanded Polystyrene Casting), works by making a foam pattern shaped like the final casting, then burying that pattern in dry sand. Molten metal is poured in under vacuum or similar process conditions; the foam pattern decomposes and vaporizes under the heat of the metal, leaving the casting behind.
Lost foam casting places heavy demands on pouring and material control. If the foam pattern, coating, vacuum level, and pouring process aren’t properly controlled, defects such as carburization, gas porosity, and slag inclusion can occur. It would be a mistake to simply assume “lost foam casting is always better quality than sand casting” — the level of process control is what actually determines final casting quality.
At its core, bimetallic composite casting joins two alloys with different properties into a single integrated part using a specific process — for example, a working layer made of a high-hardness wear-resistant alloy bonded to a base made of a high-toughness alloy, so that different zones of the part each handle a different function.
For operating conditions with both severe wear and significant impact loading, a bimetallic composite structure offers a real advantage.
Its core value lies in letting a high-hardness material handle wear resistance while a high-toughness material absorbs impact — reducing the brittle-fracture risk that can come with relying on a single high-hardness material alone.
Because the manufacturing process requires tight control over two separate alloy compositions, the melting process, pouring temperature, pouring sequence, interface bonding, solidification, and heat treatment, its process complexity and manufacturing cost are generally higher than for standard wear castings.
For high-manganese-steel wear parts such as jaw plates and liners, the complete manufacturing process can be summarized as: pattern making → mold making → melting → deoxidation/modification → pouring → cooling and solidification → shakeout and cleaning → water toughening heat treatment → machining → quality inspection → packaging and storage.
The pattern is first made based on the product drawing. Depending on the production method, this can be a sand pattern or a lost-foam pattern. Once the pattern is complete, it needs to be dimensionally inspected. For sand casting, the mold cavity, gating system, and risers also need to be designed.
High-manganese steel needs to be batched and melted according to the designed chemical composition. During melting, the key elements to control are carbon, manganese, silicon, chromium, and other alloying elements, along with harmful impurities. The composition of the molten steel directly affects the final casting’s microstructure and mechanical properties.
Before pouring, molten steel typically requires deoxidation. Depending on the specific process, modification treatment may also be applied to improve the quality of the molten metal and its solidified microstructure.
Pouring temperature needs to be carefully controlled during high-manganese-steel casting. A temperature that’s too high increases the risk of gas absorption and oxidation, while a temperature that’s too low can reduce the fluidity of the molten metal and increase the risk of cold-shut defects. Pouring temperature should therefore be determined based on the specific material, casting structure, and production process. As a reference point, high-manganese steel is typically poured at around 1500–1540°C, but actual production shouldn’t apply a fixed temperature mechanically — it should be based on the specific casting and process parameters.
After pouring, the casting enters the cooling and solidification stage. For large, thick-walled wear parts, the cooling process needs to be carefully controlled to reduce the risk of hot cracking, shrinkage cavities, shrinkage porosity, and internal stress. Once the casting has cooled, it goes through shakeout → gate and riser cutting → cleaning → grinding, removing excess gating system material, flash, and burrs.
Water toughening treatment is an extremely important step in manufacturing high-manganese-steel wear parts. The basic process involves heating → holding → rapid water quenching. One of its purposes is to improve the as-cast microstructure, giving the material a more favorable structure and toughness. High-manganese-steel water toughening treatment typically involves heating to around 1050–1100°C, holding at that temperature long enough for full transformation, then rapidly water quenching, to improve the microstructure and reduce the negative effect of unwanted carbides on performance.
If the heat-treatment temperature, holding time, or quenching rate isn’t properly controlled, the result can include insufficient toughness, increased brittleness, an unfavorable internal structure, cracking during use, and reduced wear life. This is why, when purchasing high-manganese-steel jaw plates, cone crusher liners, or similar parts, buyers shouldn’t rely on chemical composition alone — heat treatment process and test results also need attention.
Cause: As molten metal solidifies, it undergoes volumetric shrinkage — if feeding design (risering) is insufficient, shrinkage cavities or shrinkage porosity can form. Main risk: internal voids reduce the casting’s effective load-bearing capacity and can trigger cracking or even fracture under strong impact.
Cause: related to factors including gas content in the molten metal, sand permeability, coatings, the gating system, and pouring temperature. Main risk: gas porosity reduces the casting’s effective cross-section and local strength.
Sand inclusion is typically related to the molding sand, mold cavity surface, and control of the pouring process. Severe sand inclusion can affect the effective thickness of the wear layer and the structural integrity of the casting.
High-manganese steel exhibits fairly pronounced shrinkage behavior during solidification. If the casting structure, gating system, and cooling process aren’t properly designed, hot cracks can form. Hot cracking is a serious defect — some micro-cracks may not be obvious when the casting leaves the factory, but can propagate further after repeated impact once the crusher is in operation.
Carburization is a particular concern in lost foam casting. Carbon residue produced as the foam pattern decomposes at high temperature can, if the process isn’t properly controlled, affect the casting’s chemical composition and microstructure. For wear materials that require tight control of carbon content, extra care in process control is essential.
High-quality wear castings can’t be judged simply by whether they “look fine.” Quality control is best approached across the following areas.
A spectrometer is used to test the casting’s material composition, with particular focus on confirming that carbon, manganese, chromium, silicon, and other alloying elements meet the design requirements.
Hardness testing is performed based on material type and product requirements, using methods such as Brinell and Rockwell hardness testing. For wear parts, hardness testing helps confirm whether the material has achieved the required performance level.
For critical wear parts, ultrasonic testing, magnetic particle testing, or other applicable NDT methods can be used as required by the product specification, to detect certain internal or surface defects.
Length, width, thickness, mounting holes, mating surfaces, and curved-surface dimensions should all be checked against the product drawing, to confirm the wear part will fit and assemble correctly with the original crusher.
For materials that need to withstand significant impact loading, impact testing can be used to evaluate toughness. This matters especially for high-manganese-steel wear parts — the goal shouldn’t simply be maximizing hardness, but balancing hardness, toughness, and wear resistance together.
For mining procurement teams, judging wear-part quality is best approached by focusing on the following areas.
Two jaw plates or liners of the same model with similar weight don’t necessarily perform the same. What actually determines service life is a combination of material composition, casting process, heat treatment, internal soundness, and machining precision.
When purchasing, confirm the material grade and chemical composition the supplier is providing. For high-manganese-steel parts, for example, focus on confirming that manganese, carbon, and other key elements meet the design requirements.
If you’re purchasing a high-manganese-steel jaw plate or liner, it’s important to confirm whether it has undergone complete water toughening heat treatment.
It’s worth requesting the following from your supplier: material spectroscopy reports, hardness test reports, NDT reports, and dimensional inspection records. The specific test items required should be determined based on part type, material, and your procurement standards.
No single casting process suits every crusher part — but you can make a reasonable choice based on the product’s characteristics. For example:
That said, the final choice should still be made based on a combination of factors: material hardness, feed particle size, degree of impact, crusher model, production capacity, and target service life.
Q1: Why are most crusher wear parts cast rather than forged?
A: Mainly because parts like jaw plates, liners, and blow bars tend to be structurally complex and large, and casting makes it much easier to form complex curved surfaces and large dimensions.
Q2: Which is better — sand casting or lost foam casting?
A: There’s no absolute answer. For large, complex wear parts, the mature sand casting process is often the priority; for certain complex, small-to-medium, high-volume products, lost foam casting has real advantages. Final quality ultimately depends on the material, equipment, process control, and quality testing involved.
Q3: Why does high-manganese steel need water toughening heat treatment?
A: Water toughening treatment improves the as-cast microstructure and toughness of high-manganese steel, making it better suited to withstanding the impact loads generated during crushing.
Q4: Why does a casting that looks fine on the surface still fail once it’s put into service?
A: Because some defects — shrinkage porosity, internal gas porosity, micro-cracks, hot cracks, and abnormal microstructure — sit inside the casting and can’t be detected by eye. For critical wear parts, a visual inspection alone isn’t enough; it needs to be paired with appropriate non-destructive testing and material property testing.
The casting quality of crusher wear parts has a direct impact on the operating stability and overall production cost of a mining crushing line.
Today, sand casting, lost foam casting, and bimetallic composite casting are all viable processes for producing mining wear parts, each suited to different structures, materials, and production needs. For high-manganese-steel jaw plates, cone crusher liners, and similar wear parts, controlling melt composition, the pouring process, the cooling process, and water toughening heat treatment are all critical — while shrinkage cavities, shrinkage porosity, gas porosity, sand inclusion, hot cracking, and failed heat treatment can all become the root cause of premature wear-part failure. Mining procurement teams shouldn’t select crusher wear parts based on price and weight alone; only by considering material, casting process, heat treatment, machining, and quality testing together can you genuinely lower the total cost of ownership for wear parts and reduce the risk of unplanned downtime on the production line.
If you’re sourcing jaw plates for a jaw crusher, cone crusher parts, blow bars for an impact crusher, hammers for a hammer crusher, or other mining wear castings, it’s worth providing your supplier with the specific crusher model, material type, feed particle size, and operating conditions, so the right material and casting process can be selected based on your actual application.
