Quick Answer
Evidence scope: This article uses documented product specifications, but no customer-specific implementation or field-performance case was provided. Application guidance is a selection framework and should be confirmed through a controlled trial under the reader’s drilling conditions.
A custom carbide grade RFQ fails when it specifies only dimensions and hardness. You must specify the dominant failure mode (fracture vs. wear), the rock or coal formation characteristics, and the machine operating parameters. Ruixin Tungsten Carbide offers custom grade formulation—not just catalog grades—where alloy composition is designed to your performance spec. Because a higher-hardness, finer-grain grade like Ruixin SR7X (HRA 91.0) is positioned for wear resistance, while a higher-toughness grade like Ruixin SR10C (HRA 88.0) is positioned for impact survival, your RFQ must give the supplier enough data to choose the correct starting point. The difference between a successful custom grade and a failed one is almost always the quality of the application data you provide before the first sample is produced.
Why This Problem Happens
Most mining tool RFQs fail because they treat carbide as a commodity with one variable—hardness—when the real decision is a system of trade-offs. Procurement teams routinely send drawings with only a hardness value and a dimension, expecting the supplier to infer the rest. The supplier then has no way to know whether the tool will face impact fracture, abrasive wear, or a combination of both, and the resulting grade selection is a guess dressed up as engineering.
The problem surfaces in three distinct ways on site. Premature fracture occurs when tips break or chip within days of installation, often because a wear-optimized grade was used in an impact-dominated application. Rapid wear happens when tools dull quickly, slowing penetration rates and increasing cost per meter, because a toughness-optimized grade was used in an abrasive formation. Batch inconsistency appears when samples pass qualification but production batches perform differently, causing unpredictable tool life and unplanned downtime across your fleet.
The root cause is the same in all three cases: the RFQ did not communicate the application conditions that determine the correct WC-Co microstructure. For cemented carbide, hardness, cobalt-binder level, WC grain size, and flexural strength must be considered together. A higher-hardness, finer-grain grade is generally positioned toward wear resistance, while a higher-toughness grade is positioned toward impact survival. This is a selection direction, not a fixed field-performance conversion, and it requires application data to execute properly.
The buyer context matters. Procurement managers at mining companies, engineers at OEM tooling manufacturers, and technical buyers at tunneling contractors all need different data from a custom grade supplier. The RFQ is the single document that aligns all three. When it is incomplete, the supplier cannot engineer a solution—they can only quote a product. When it is complete, the supplier can diagnose the failure mode and formulate a grade that addresses the root cause rather than the symptom. The cost of a poorly specified RFQ is not just a bad batch of carbide; it is the downtime, replacement labor, and lost production that follow.
How the Available Routes Differ
There are two routes to a custom carbide grade: catalog selection and custom formulation—and they differ in how much application data the supplier needs from you. Catalog selection works when your application matches a proven category with existing grades. Custom formulation becomes necessary when your conditions fall outside those categories or when you are experiencing repeat failures that a grade swap cannot solve. Understanding which route you need before you write the RFQ saves weeks of back-and-forth.
| Route | What You Get | What Supplier Needs | Best For |
|---|---|---|---|
| Catalog Grade Selection | Existing grade (e.g., Ruixin SR8C) with fixed specs | Application category only (e.g., “road milling”) | Standard conditions, proven applications, faster sampling |
| Custom Grade Formulation | Alloy composition designed to your performance spec | Rock type, machine model, failure mode, operating parameters | Non-standard formations, repeated failures, specific performance targets |
The decision between routes is not about quality—it is about fit. A balanced starting point for variable service conditions like roadheaders should be verified with your supplier: ask them to confirm hardness, flexural strength, grain size, and how the grade performs under your specific loads. But if your failure mode is consistently fracture in a specific coal seam, a custom formulation that adjusts cobalt content or shifts grain size may solve the problem in a way a catalog grade cannot. Ask your supplier to explain the tradeoffs in lead time and precision so you can decide which route fits your operating conditions.
The threshold for choosing custom formulation over catalog selection is repeat failure. If you are seeing the same failure mode across multiple bits or batches, a catalog grade swap is unlikely to fix it. You need a formulation change. A supplier with in-house production capability—like Ruixin Tungsten Carbide, which manufactures rather than trades—can adjust the alloy composition and test the result. A trading company can only offer you a different catalog number. This is the practical difference between the two routes, and it should drive your supplier selection as much as your grade selection.
What to Test Before Choosing
Before you commit to a custom grade, you need a controlled site trial that isolates the grade variable—everything else must stay constant. This is the only way to know whether a formulation change actually solves your problem. Changing the grade and the bit geometry and the operating parameters at the same time makes it impossible to attribute any improvement to the carbide itself. The trial protocol matters as much as the grade specification.
1. Define the Failure Mode
Your RFQ must state whether the dominant failure is fracture or wear. This single data point determines the cobalt and grain size direction. If you do not know which failure mode dominates, collect failed tools and examine the fracture surfaces before writing the RFQ. Chipped or broken tips indicate impact overload. Worn flats or dulled cutting edges indicate abrasive wear. Mixed patterns indicate variable conditions that need a balanced grade.
| Observed Failure | Likely Direction | Ruixin Starting Point |
|---|---|---|
| Tip chipping, breakage, pull-out | Higher toughness | SR10C (HRA 88.0, ≥ 2,200 MPa) |
| Rapid wear, dulling, flat spots | Higher wear resistance | SR7X (HRA 91.0, 1.0–1.2 µm) |
| Mixed or variable conditions | Balanced | SR8C (HRA 89.0, 2.0–3.0 µm) |
2. Specify the Application Data
Include these in your RFQ to give the supplier the full picture: Formation type—rock name, hardness (Mohs or Protodyakonov coefficient), abrasiveness, structure (fractured, massive, mixed); Machine model—rig, shearer, roadheader, or milling machine model, noting that Ruixin supports OEM compatibility for Bauer, Liebherr, and Soilmec rotary rigs; Operating parameters—cutting speed, impact energy, water/flushing conditions; Current grade and failure history—what you are using now and how it fails. This data set turns the RFQ from a purchase order into an engineering brief.
3. Run a Controlled Trial
Use the incumbent grade as the control and test the candidate grade with the same bit body, button geometry, hammer, operating window, and comparable formation interval. Record the batch material test report, drilled length or hole count, wear-flat progression, button fractures, pulls, penetration-rate trend, and relevant formation observations. Compare results across multiple bits before making a fleet-level or production-order decision. A single bit test is a data point, not a conclusion.
The qualification checklist for your RFQ:
- [ ] Dominant failure mode stated (fracture vs. wear)
- [ ] Formation characteristics included (rock type, hardness, abrasiveness)
- [ ] Machine model and operating parameters specified
- [ ] Current grade and failure history documented
- [ ] Batch material test report requested (density, HRA, flexural strength)
- [ ] Controlled trial protocol agreed with supplier
Carbide Grade Hardness and Toughness Specifications for Mining
The hardness-toughness trade-off is the central decision in carbide grade selection for mining tools, and it is governed by two variables: cobalt binder percentage and WC grain size. These two parameters determine where a grade sits on the wear-resistance versus impact-survival spectrum. Every other property—density, flexural strength, thermal conductivity—is downstream of this fundamental trade-off. Understanding it is the difference between specifying a grade and guessing at one.
Cobalt binder percentage is the primary toughness lever. Higher cobalt content increases flexural strength and impact survival but lowers hardness (HRA) and wear resistance. This is why Ruixin SR10C, positioned for higher-toughness impact applications, sits at HRA 88.0 with flexural strength ≥ 2,200 MPa, while Ruixin SR7X, positioned for high wear resistance, reaches HRA 91.0 with a finer grain size of 1.0–1.2 µm. The same logic applies across the grade range: you trade hardness for toughness as cobalt increases.
WC grain size is the secondary lever, and it is the most under-specified parameter in mining tool RFQs. In the same cobalt content range, a finer grain size (1.0–1.2 µm) produces higher hardness and better wear resistance but lower impact toughness. A coarser grain size (2.0–3.0 µm) produces the opposite: better impact survival but lower hardness. Ruixin SR8C uses 2.0–3.0 µm grain size at HRA 89.0 to balance these competing demands for variable service conditions like roadheaders and road milling.
The practical implication for your RFQ is that hardness alone is meaningless without grain size and cobalt content. A hardness value of HRA 89.0 could describe a fine-grain, low-cobalt grade or a coarse-grain, high-cobalt grade with completely different field behavior. When you specify only hardness, you leave the supplier to guess at the microstructure. When you specify the failure mode and formation conditions, the supplier can select the correct combination of cobalt and grain size to hit the performance target.
Carbide Grade Comparison for Rock Drilling vs Coal Mining
Rock drilling and coal mining place fundamentally different demands on carbide grades, and the RFQ must reflect this difference or you will receive the wrong material. Rock drilling is dominated by impact loading and abrasive formations that require a grade matched to both the rock’s abrasiveness and the impact energy of the drilling system. Coal mining, particularly longwall shearer and roadheader applications, involves complex strata where the tool must handle both impact from harder inclusions and wear from abrasive coal and rock.
For rock drilling applications, the grade direction follows the rock’s abrasiveness and the impact level. Highly abrasive, lower-impact formations favor a wear-resistant grade like Ruixin SR7X at HRA 91.0 with fine grain size. Impact-dominated hard rock favors a tougher grade like Ruixin SR10C at HRA 88.0. The correct DTH grade should be chosen from formation information, observed button failure mode, bit and hammer configuration, and a controlled site trial—not from a general catalog recommendation.
For coal mining applications, the formulation must balance impact toughness with wear resistance because the tool faces variable conditions within a single shift. Coal seams contain harder inclusions, rock partings, and abrasive material that change the loading pattern unpredictably. Ruixin SR8C at HRA 89.0 with flexural strength ≥ 2,200 MPa and grain size 2.0–3.0 µm is the balanced starting point for these variable conditions, which is why it appears across both roadheader and road milling applications.
The comparison comes down to failure mode probability. In rock drilling, you can often predict whether fracture or wear will dominate based on the formation. In coal mining, you cannot, because the strata change. Your RFQ should state which situation you are in. If you are drilling a known granite formation, specify the rock hardness and abrasiveness. If you are cutting a coal seam with unknown partings, specify the mixed-condition requirement and ask for a grade that handles both wear and impact without excelling at either.
Cobalt Binder Percentage for Mining Carbide Inserts
Cobalt binder percentage is the single most important specification in your RFQ because it directly controls the fracture-versus-wear balance of the finished tool. The binder holds the tungsten carbide grains together and provides the toughness that prevents catastrophic fracture under impact loading. But every percentage point of cobalt added reduces hardness and wear resistance. This is not a flaw in the material—it is the fundamental trade-off that makes carbide engineering possible.
The selection logic is straightforward when you know the failure mode. If your tools are fracturing, you need more cobalt. If they are wearing out too fast, you need less. Ruixin SR7X at HRA 91.0 with grain size 1.0–1.2 µm is positioned for high wear resistance in abrasive, lower-impact service. Ruixin SR10C at HRA 88.0 with flexural strength ≥ 2,200 MPa is positioned for higher-toughness, impact-dominated service. Ruixin SR8C at HRA 89.0 splits the difference for variable conditions.
The threshold for changing cobalt content is the observed failure mode, not the hardness spec. If you are seeing fracture, increasing cobalt by one or two percentage points may solve the problem while maintaining acceptable wear resistance. If you are seeing rapid wear, decreasing cobalt and adjusting grain size may extend tool life without introducing fracture risk. These adjustments are exactly what custom grade formulation enables, and they are impossible with a fixed catalog grade.
Your RFQ should state the target cobalt range or, better, describe the failure mode and let the supplier recommend the range. A supplier with in-house production capability can adjust the formulation and verify the result with material testing. A trading company can only offer you existing grades. This is why the cobalt specification in your RFQ is not just a technical detail—it is a test of whether your supplier can actually engineer a solution or only sell you a product.
How to Specify Carbide Grade in RFQ for Mining Equipment
A complete RFQ for custom carbide grade formulation contains seven data fields, and missing any one of them forces the supplier to make an assumption that may be wrong. The seven fields are: application category, formation type, machine model, operating parameters, current grade, failure mode, and performance target. Each field narrows the grade selection range and reduces the risk of a failed trial. Together, they transform the RFQ from a purchase order into an engineering specification.
The application category tells the supplier which product line applies. A rotary drilling rig needs different carbide than a longwall shearer. Ruixin’s carbide cutter bits for rotary drilling are grades matched to rock abrasiveness and impact level, with OEM support for Bauer, Liebherr, and Soilmec rigs. Coal tooth carbide tips for shearer and roadheader picks prioritize high impact toughness plus wear resistance in complex strata. Road milling carbide picks require stable wear performance across long production runs with consistent batch quality. Shield machine carbide tips for TBM applications target wear-resistant performance in medium-hard formations.
Before finalizing the specification, compare the required evidence and application inputs in the Custom Carbide Grade Formulation for Mining Tools.
The formation type and machine model give the supplier the physical context. Rock hardness, abrasiveness, and structure determine the wear regime. The machine model determines the impact energy and cutting geometry. Operating parameters—cutting speed, impact energy, flushing conditions—complete the picture. Current grade and failure history tell the supplier what has already been tried and what went wrong. The performance target defines what success looks like: longer tool life, faster penetration, lower cost per meter, or some combination.
The RFQ format matters as much as the content. Send the data in a structured format—a table, a checklist, or a technical questionnaire—rather than a free-form email. This makes it easy for the supplier to process and reduces the chance of missing information. Ruixin’s sample process is designed for this: submit application details, the engineer confirms grade and dimensions, then a sample order leads to volume supply. The better your RFQ, the faster this process works.
Best Carbide Grade for Mining Picks and Cutting Tools
There is no single best carbide grade for all mining picks and cutting tools—the correct grade is the one that matches your dominant failure mode and formation conditions. This is the most common misconception in mining tool procurement, and it leads buyers to chase a universal solution that does not exist. The engineering reality is that grade selection is conditional: the best grade for a high-impact coal seam is the worst grade for an abrasive sandstone, and vice versa.
For impact-dominated applications where tools fracture or chip, the engineering starting point is a higher-toughness grade. Ruixin SR10C at HRA 88.0 with flexural strength ≥ 2,200 MPa is positioned for this service because the higher cobalt content provides the toughness needed to survive impact loading. For abrasive, lower-impact applications where tools wear out too quickly, the starting point is a wear-resistant grade. Ruixin SR7X at HRA 91.0 with fine grain size of 1.0–1.2 µm is positioned for this service because the higher hardness and finer grain structure resist abrasive wear.
For variable conditions that include both impact and abrasion, the balanced choice is Ruixin SR8C at HRA 89.0 with grain size 2.0–3.0 µm. This grade does not excel at either extreme, but it survives both without premature failure. This is why SR8C appears across roadheader, road milling, and variable rock drilling applications. The trade-off is acceptable because the alternative—a grade optimized for one extreme—fails quickly when conditions shift to the other.
The selection logic bridge is the failure mode. If your dominant failure is fracture, move toward SR10C. If it is wear, move toward SR7X. If it is mixed, start with SR8C and adjust based on trial results. Your RFQ should state the observed failure mode and ask the supplier to recommend the starting point. This is not a sign of indecision—it is the correct way to use the supplier’s engineering expertise. The best grade for your application is the one that survives your specific conditions, and only a controlled trial can confirm it.
Carbide Wear Parts for Mining: Grade Selection Guide
Carbide wear parts for mining—strips, liners, nozzles, and custom components—follow the same grade selection logic as cutting tools, but the failure mode weighting shifts toward pure abrasion. Wear parts do not typically experience the same impact loading as picks and buttons, so the grade can be optimized for hardness and wear resistance without sacrificing as much toughness. This is why Ruixin SR7X at HRA 91.0 with grain size 1.0–1.2 µm appears across wear-resistant component applications.
The selection criteria for wear parts are: the abrasiveness of the material being handled, the impact level (if any), the operating temperature, and the required service life. For highly abrasive slurries or bulk materials with minimal impact, a fine-grain, high-hardness grade is the right direction. For applications with occasional impact—such as crusher liners or chute liners that take rock impacts—a balanced grade like Ruixin SR8C provides the toughness reserve to survive those events.
The trade-off in wear parts is between initial cost and total cost of ownership. A harder grade may cost more per kilogram but last longer in abrasive service, reducing replacement frequency and downtime. A tougher grade may be cheaper initially but fail faster in pure abrasion, increasing total cost. Your RFQ should state the dominant wear mechanism and the target service life so the supplier can optimize the formulation for total cost, not just initial price.
Batch consistency is critical for wear parts because a single weak batch can fail prematurely and contaminate the entire system. Request a material test report for each batch, including density, hardness (HRA), and flexural strength. Ruixin Tungsten Carbide can provide an ISO certificate, material test report, and batch QC report for specified orders. Ask your supplier to confirm which documents are included with your shipment before ordering. This is the verification step that separates a reliable custom grade supplier from a trader.
Recommended Next Step
Send your application data—not just a drawing—to Ruixin Tungsten Carbide for a custom grade recommendation. The fastest path to the right grade is a complete RFQ. Include your rock type, machine model, current grade, and the failure mode you are seeing. Ruixin’s technical consultation supports grade selection, not just order taking. For rotary drilling applications, send your rig model and ground conditions for a custom recommendation. For rotary drilling carbide inserts, the grade must match rock abrasiveness and impact level. For coal tooth carbide tips, the formulation must balance impact toughness with wear resistance in complex strata. For road milling carbide inserts, batch consistency matters as much as hardness. For shield machine carbide tips, medium-hard formations require wear-resistant grades. For DTH drill bit carbide buttons, the grade must be matched to rock abrasiveness and button geometry.
The decision rule: If you are seeing repeated failures, do not reorder the same grade. Send your failure data and application conditions to Ruixin and get a formulation designed for your specific service conditions. The cost of a failed trial is small compared to the cost of a fleet running on the wrong grade for months.
FAQ
What is the best custom carbide grade formulation for mining tools with high impact and abrasion?
There is no single universal grade. The correct formulation depends on your dominant failure mode. For impact-dominated service, a higher-toughness grade like Ruixin SR10C (HRA 88.0, flexural strength ≥ 2,200 MPa) is the engineering starting point. For abrasive, lower-impact wear, Ruixin SR7X (HRA 91.0, grain size 1.0–1.2 µm) is positioned for high wear resistance. Specify the rock type, machine model, and observed failure mode in your RFQ to get a conditional recommendation.
How does cobalt binder percentage affect carbide grade performance in mining applications?
Cobalt content is the primary toughness lever. Higher cobalt increases flexural strength and impact survival but lowers hardness (HRA) and wear resistance. Ruixin SR8C at HRA 89.0 balances wear and toughness for variable conditions, while SR10C at HRA 88.0 prioritizes impact survival. Your RFQ should state whether your failure mode is fracture or wear, as this determines the target cobalt range.
What documents should I request from a carbide supplier to verify custom grade batch consistency?
Request a Material Test Report (MTR) for each batch, including density, hardness (HRA), and flexural strength. Ruixin Tungsten Carbide can provide an ISO certificate, material test report, and batch QC report for specified orders. Ask your supplier to confirm which documents are included with your shipment before ordering.
How do I match carbide grade to rock abrasiveness for DTH drilling applications?
Match the grade to the rock’s abrasiveness and the impact level of the drilling system. For highly abrasive, lower-impact formations, Ruixin SR7X at HRA 91.0 with fine grain size (1.0–1.2 µm) is positioned for wear resistance. For impact-dominated hard rock, Ruixin SR10C at HRA 88.0 with higher toughness is the starting point. The correct DTH grade should be chosen from formation information, observed button failure mode, bit and hammer configuration, and a controlled site trial.
What is the difference between catalog carbide grades and custom grade formulation?
Catalog grades are fixed formulations designed for general application categories. Custom grade formulation adjusts the alloy composition—cobalt content, grain size, and other variables—to your specific performance spec. Ruixin Tungsten Carbide offers both routes. Custom formulation is the right choice when you have a non-standard formation, repeated failures, or specific performance targets that catalog grades cannot meet.
Performance note: The material values shown are grade specifications and engineering selection references, not guaranteed field-life results. Drilling life and cost per meter vary with rock abrasiveness and structure, button geometry, bit and hammer design, operating parameters, flushing, and production-batch conformity. Any numeric field result cited is limited to the identified application and should be validated by a controlled trial under the buyer’s actual conditions.
Get a Custom Carbide Grade Formulation Recommendation
Ready to specify your custom grade? Send your rock type, machine model, current grade, and failure mode to Ruixin Tungsten Carbide. The engineering team will confirm a grade direction and dimensions for your application. This is a technical consultation, not just a quotation—you will receive a recommendation based on your specific service conditions, not a catalog listing.
Email: info@ruixintungstencarbide.com
Phone: +86-15253178777
WhatsApp: +86-15253178777
Link: https://ruixintungstencarbide.com/contact/
Get a Custom Grade Recommendation
English 
Russian 
Spanish 
French