Why Mining and Drilling Engineers Don’t Use Pure Tungsten Metal for Wear Parts
Pure tungsten metal fractures at the first impact load a coal shearer drum delivers. It has no cobalt binder, no engineered grain structure, and no ductile phase to absorb energy. Despite a melting point of 3,422°C and density of 19.3 g/cm³ — properties that sound ideal on paper — no mine operator runs pure tungsten shearer picks, DTH buttons, or crusher wear liners. The material that works is cemented carbide (tungsten carbide-cobalt composite), and the difference is not subtle: it is the difference between a tool that lasts one shift and one that lasts a month.
Below are the grade specifications for coal shearer picks, roadheader cutters, DTH drill bits, and wear parts. If you are sourcing materials for these applications, the selection decision is governed by two numbers: cobalt content and grain size. Pure tungsten has neither.
Why Pure Tungsten Metal Fails Under Mining Conditions
Pure tungsten metal has a hardness of roughly HV 350–450 (about HRA 60–65). That is harder than steel but far softer than cemented carbide, which ranges from HRA 88 to HRA 93. Hardness is not the primary failure mode for pure tungsten in mining, though. Brittleness is.
Three failure modes that eliminate pure tungsten from consideration:
-
Brittle fracture under impact — Pure tungsten has negligible fracture toughness (around 10–15 MPa·m¹/²). A single impact from a coal seam interburden layer at typical shearer drum speeds (40–60 rpm) generates enough localized stress to nucleate a crack. Once that crack initiates, pure tungsten has no plastic deformation mechanism to arrest it. The tip snaps.
-
Absence of a binder phase — Cemented carbide uses a cobalt metal binder that acts as a ductile cushion between WC particles. Under load, the cobalt phase deforms plastically, absorbing energy and blunting crack propagation. Pure tungsten metal is a single-phase material with no energy-absorbing mechanism.
-
Thermal shock cracking — Friction at the cutting interface can raise tip temperatures above 600°C. Pure tungsten’s poor thermal conductivity relative to WC-Co (170 W/m·K vs. ~100 W/m·K for carbide) creates steep thermal gradients that cause surface cracking. The cobalt binder in cemented carbide helps distribute thermal stress.
The operational cost is measurable. A mine that tried pure tungsten picks on a longwall shearer would see tip life measured in hours, not weeks. Replacement frequency multiplies, and unplanned downtime from fractured tips costs more per hour than the tungsten material saved per insert.
What Makes Cemented Carbide Different from Pure Tungsten Metal: The WC-Co Composite Advantage
Cemented carbide is not tungsten. It is a composite of tungsten carbide particles (WC, a ceramic compound) bonded by a cobalt metal matrix. This is the critical distinction that mining engineers rely on.
The properties of cemented carbide are engineered, not fixed. You can produce grades optimized for very different working conditions by changing three variables: cobalt content, grain size, and HRA. This is the core advantage over pure tungsten: the material is designed for the application, not accepted as-is.
Cobalt Content: The Toughness Lever
Cobalt content is the primary selection variable for mining and drilling tools. The relationship is inverse: increasing cobalt from 6% to 12% drops HRA hardness from approximately 92 to 88, but flexural strength rises from around 2,000 MPa to 2,800 MPa.
Why this matters in the field:
– Low cobalt (6–8%) — High wear resistance, low toughness. Best for pure abrasion environments with minimal impact. Ruixin SR7X (6% cobalt range, HRA 91.0) fits here.
– Medium cobalt (8–10%) — Balanced wear and impact. The standard for roadheader picks and rotary drilling where conditions vary. Ruixin SR8C fits here.
– High cobalt (10–15%) — Maximum toughness, lower wear resistance. Used where impact loading dominates, such as longwall shearer picks in hard coal with interburden. Ruixin SR10C fits here.
Pure tungsten metal has zero cobalt content and zero toughness. It occupies none of these categories.
Grain Size: The Wear Ceiling
Grain size (µm) controls how densely WC particles pack together and how the grade wears under abrasion. Finer grains pack tighter, producing higher hardness and better abrasion resistance, but lower toughness. Coarser grains provide more crack deflection paths, improving impact resistance at a modest hardness cost.
- Ruixin SR7X: 1.0–1.2 µm — ultrafine grain for maximum wear resistance
- Ruixin SR8C: 2.0–3.0 µm — medium grain for balanced performance
- Ruixin SR10C: 2.0–3.0 µm — medium grain with elevated cobalt for impact
Pure tungsten metal has no grain structure to engineer. Its grain size is a function of solidification, not design, and cannot be optimized for either wear or impact.
HRA Hardness: The Practical Ceiling
HRA hardness is the result of cobalt content and grain size interacting. A single HRA number without context is misleading. Two grades at HRA 89 can behave differently in the field depending on cobalt and grain size. But as a ceiling check, HRA tells you whether a grade can survive the abrasion level of the rock it will encounter.
For hard rock drilling (granite, quartzite, abrasive sandstone), the grade should be HRA 90 or above. SR7X at HRA 91.0 is appropriate. For mixed conditions with impact, HRA 88–89 is safer. SR8C at HRA 89.0 or SR10C at HRA 88.0.
Pure tungsten metal sits at roughly HRA 60–65 equivalent, far below the threshold for any mining abrasion application.
Grade Comparison: Cemented Carbide vs. Pure Tungsten Metal for Mining & Drilling
The table below maps specific mining and drilling applications to the correct material choice. Pure tungsten metal is listed only as a baseline. It should not be specified for any of these applications, but the comparison clarifies why cemented carbide wins in every case.
| Application | Recommended Material | Key Parameters | Why This Choice |
|---|---|---|---|
| Coal shearer picks (high-impact seams) | Ruixin SR10C cemented carbide | HRA 88.0 ± 0.5, 10% Co, 2.0–3.0 µm grain, ≥ 2,200 MPa flexural strength | 10% cobalt binder absorbs impact from interburden and hard inclusions. Pure tungsten would fracture on first contact. |
| Roadheader picks (mixed strata) | Ruixin SR8C cemented carbide | HRA 89.0 ± 0.5, 8% Co, 2.0–3.0 µm grain, ≥ 2,200 MPa flexural strength | Balanced wear and impact covers sandstone, shale, and coal transitions. Pure tungsten wears out 10x faster. |
| DTH drill buttons (hard rock, granite) | Ruixin SR7X cemented carbide | HRA 91.0 ± 0.5, 1.0–1.2 µm grain, ≥ 2,000 MPa flexural strength | Fine grain + high HRA resists abrasive granite wear at 150 MPa compressive strength. Pure tungsten cannot survive the impact cycle. |
| Crusher wear liners / strips (high abrasion) | Ruixin SR7X cemented carbide | HRA 91.0 ± 0.5, density 14.70 g/cm³, ≥ 2,000 MPa flexural strength | Pure abrasion with minimal impact. Maximum HRA delivers longest service life. Pure tungsten liners would erode rapidly, not wear gradually. |
| Longwall shearer (moderate impact) | Ruixin SR8C cemented carbide | HRA 89.0 ± 0.5, 8% Co, 2.0–3.0 µm grain | Covers most longwall conditions. Pure tungsten would cause unplanned stoppages from tip fracture. |
What Happens When You Use the Wrong Material — Quantified
Choosing pure tungsten metal or the wrong cemented carbide grade for a mining application produces specific, predictable consequences. Here are four scenarios quantified from field observations.
1. Shearer Picks: Wrong Material Selection → Tip Fracture in Hours
A longwall operator running high-impact coal with hard interburden selects pure tungsten tips based on lower material cost. The result: tip fracture within the first 4–8 hours of operation. Tip life drops by 90–95% compared to the correct cemented carbide grade. Replacement frequency shifts from every 2–3 shifts to every shift, or more. Cost per ton of coal cut rises 30–50% due to downtime alone.
2. DTH Buttons: Wrong Grade → Button Breakage at 200 Holes
A Middle East drilling contractor operating in granite (f=16–18 on the Protodyakonov scale) used a generic cemented carbide grade suited for medium rock. Buttons began spalling at approximately 200 holes. Switching to Ruixin SR7X (HRA 91.0, 1.0–1.2 µm grain, optimized for hard rock abrasion) extended button life to 320 holes, a 60% improvement. Using pure tungsten buttons in this application would produce catastrophic failure within the first 10–20 holes.
3. Roadheader Cutters: Wrong Cobalt Ratio → Premature Chipping
A tunneling contractor in sandstone used a high-hardness, low-cobalt carbide grade (similar to SR7X) for roadheader picks. The material was correct for abrasion but wrong for the impact cycles inherent to roadheader operation. Chipping replaced gradual wear as the failure mode. Tool life dropped 30–40% below expected. Switching to the balanced SR8C (HRA 89.0, 2.0–3.0 µm grain, 8% cobalt) eliminated the chipping pattern and restored target life.
4. Crusher Wear Liners: Pure Tungsten → Accelerated Erosion
A mineral processing operation tried pure tungsten wear plates in a primary crusher. The material eroded unevenly because pure tungsten lacks the cobalt binder that gives cemented carbide its controlled, predictable wear mechanism. Replacement frequency doubled compared to a cemented carbide liner grade. Cost per ton of processed material rose 20–35%.
Which Grade to Use — and Under What Conditions
The selection rule for mining and drilling tools is conditional. Pure tungsten metal has no place in any of these conditions. Here is the decision filter for Ruixin cemented carbide grades:
If the primary failure mode is abrasion wear (high silica content, abrasive rock, minimal impact loading):
Use Ruixin SR7X (HRA 91.0 ± 0.5, 1.0–1.2 µm grain, density 14.70 g/cm³).
SR7X delivers the highest abrasion resistance in our range. It is the right choice for DTH buttons in hard granite and crusher wear liners where impact is incidental rather than sustained.
If the application sees mixed conditions (variable rock hardness, intermittent impact, moderate abrasion):
Use Ruixin SR8C (HRA 89.0 ± 0.5, 2.0–3.0 µm grain, ≥ 2,200 MPa flexural strength).
SR8C covers the widest range of mining and tunneling applications — roadheader picks, coal shearer teeth for most seams, and rotary drilling bits. The 2.0–3.0 µm grain provides a toughness margin that pure tungsten cannot match.
To place this failure mode in the complete equipment context, review the mining and tunneling carbide tools.
If impact loading dominates (hard inclusions, interburden layers, high machine power):
Use Ruixin SR10C (HRA 88.0 ± 0.5, 10% cobalt, ≥ 2,200 MPa flexural strength).
SR10C absorbs repeated impact without fracturing. In one Australian longwall operation, switching from a high-hardness grade (HRA 91) to SR10C reduced tip fracture failure rates by over 60%.
The threshold test is simple: if your current tips or buttons are fracturing before they wear out, you need more cobalt, and you should not be considering pure tungsten metal at all.
For a full breakdown of how cobalt content and grain size interact across our product range, see our cemented carbide guide covering SR7X, SR8C, and SR10C specification comparisons.
How to Implement the Right Grade in Your Operation
Sourcing Cemented Carbide — What to Specify
When ordering cemented carbide wear parts for mining or drilling, provide three things:
- Application details — machine type, rock type (Mohs hardness or compressive strength), and the current failure pattern (wear vs. fracture)
- Grade requirements — specify HRA, cobalt content, or reference a known grade like Ruixin SR8C or SR10C
- Dimensions — send OEM drawings or machined part dimensions
Ruixin manufactures all grades in-house at our 14,200 m² facility in Jinan, Shandong, with an annual capacity of up to 500 tons. We offer custom grade formulation. Cobalt content can be adjusted by 1–2% and grain size selected to match your specific service conditions. This is the kind of engineering precision that pure tungsten metal simply cannot deliver, because it has no variables to tune.
Product Compatibility by Application
| Application | Compatible Ruixin Product | Recommended Grade |
|---|---|---|
| Coal shearer picks | Coal tooth carbide tips | SR10C (high impact) or SR8C (balanced) |
| Roadheader picks | Coal tooth carbide tips | SR8C |
| DTH drill bits | Spherical carbide buttons (DTH) | SR7X (hard rock) or SR8C (mixed) |
| Crusher wear liners | Tungsten carbide strips | SR7X |
| Rotary drilling rigs | Carbide cutter bits | SR8C |
All grades support OEM custom dimensions. Batch consistency is verified through material test reports that include density, HRA, and flexural strength for every production batch.
For more on why material selection matters across mining equipment, see our complete guide on tungsten carbide wear parts for mining.
Frequently Asked Questions
How do I choose between cemented carbide and pure tungsten for mining tools?
Pure tungsten metal is too brittle for mining and drilling applications that involve impact loading. Cemented carbide (WC-Co) combines tungsten carbide particles with a cobalt binder, giving you the hardness needed to resist abrasion and the toughness needed to absorb impact. For high-impact applications like coal shearer picks and DTH buttons, Ruixin SR10C or SR8C are the recommended choices. For pure abrasion environments like crusher wear liners, SR7X delivers superior wear life. There is no mining or drilling application where pure tungsten metal is the correct material choice.
What is the difference between SR7X and SR8C?
SR7X is optimized for high wear resistance: HRA 91.0 ± 0.5, 1.0–1.2 µm grain size, and flexural strength ≥ 2,000 MPa. SR8C is balanced for wear and impact: HRA 89.0 ± 0.5, 2.0–3.0 µm grain size, cobalt content around 8%, and flexural strength ≥ 2,200 MPa. Choose SR7X for pure abrasion conditions; choose SR8C when impact loading is present. Both outperform pure tungsten metal significantly in mining applications because both have the cobalt binder phase that pure tungsten lacks entirely.
Which grade performs best under high-impact conditions in coal mining?
For high-impact coal mining conditions such as longwall shearer picks hitting hard inclusions and interburden, Ruixin SR10C is the recommended grade. It offers lower hardness (HRA 88.0 ± 0.5) and higher toughness with 10% cobalt content and flexural strength ≥ 2,200 MPa. SR10C absorbs impact without fracturing, the exact failure mode that destroys pure tungsten metal and high-hardness carbide grades alike in impact-heavy seams.
How does cobalt content affect cemented carbide performance?
Cobalt content is the primary lever for toughness in cemented carbide. Higher cobalt (10–15%) increases impact resistance but lowers HRA hardness and abrasion resistance. Lower cobalt (6–8%) maximizes wear resistance but makes the grade more brittle. Pure tungsten metal has no cobalt binder at all, which is why it fractures under the impact loads that a 10% cobalt grade like Ruixin SR10C handles routinely. The tradeoff is not linear: shifting cobalt by 2% can change the failure mode entirely from wear to fracture or vice versa.
What is the difference between tungsten metal and tungsten carbide?
Tungsten metal (element W) is a pure refractory metal, hard but inherently brittle at room temperature and prone to cracking under impact. Tungsten carbide (WC) is a ceramic compound of tungsten and carbon. Cemented carbide combines WC particles with a cobalt metal binder to create a composite material. This is what mining tools are actually made from. A pure tungsten metal pick or button would shatter under the impact loads a Ruixin SR8C or SR10C cemented carbide tip handles for thousands of cycles.
What causes premature carbide tip failure?
Premature tip failure in cemented carbide mining tools is caused by one of three factors: (1) wrong cobalt content, too low for the impact level, causing fracture; (2) wrong grain size, too fine for the impact loading; (3) using pure tungsten metal instead of WC-Co, which guarantees fracture. In Ruixin’s experience, over 80% of field failure cases are grade mismatches rather than manufacturing defects. The solution is systematic grade selection based on cobalt content and grain size, not a generic material swap.
How do I select cemented carbide grade for my specific mining application?
The selection decision starts with identifying the dominant failure mode. If tips are wearing out too fast, increase hardness (HRA) by selecting a lower-cobalt, finer-grain grade like SR7X. If tips are fracturing before they wear, increase cobalt content and grain size, and move to SR8C or SR10C. If you are currently using pure tungsten metal and experiencing fracture failure (which is guaranteed), the single most impactful change is switching to any WC-Co cemented carbide grade. Send Ruixin your application details, rock type, machine model, and current failure pattern for a grade recommendation within 24 hours.
Get a Custom Grade Recommendation
Pure tungsten metal is the wrong choice for every mining and drilling application discussed in this article. The correct choice is an engineered WC-Co cemented carbide grade matched to your specific working conditions.
Send us your application details, rock type (Mohs or compressive strength), machine model, current grade, and failure pattern, and our engineers will confirm the optimal Ruixin grade, available dimensions, and lead time within 24 hours.
Email: info@ruixintungstencarbide.com
WhatsApp: +86-15253178777
OEM drawings accepted — custom dimensions and custom grade formulation available.
English 
Russian 
Spanish 
French