Cobalt Alloy Hex Bars: Engineered for Extreme Wear and High-Temperature Performance
Table of Contents:
In a Gulf of Mexico deepwater drilling operation, standard nickel alloy valves eroded rapidly under abrasive slurries and 900°C conditions, causing leaks and halting production for weeks.
Switching to Cobalt Alloy Hex Bars restored integrity, showcasing their unmatched wear resistance and thermal stability that now powers reliable operations globally.
Specifications and Standards
Cobalt Alloy Hex Bars adhere to AMS 5759 for bars, AMS 5894 for Stellite variants, ASTM F90, DIN 2.4964, and EN ISO 5832-5 (CoCr20W15Ni), guaranteeing high-temperature strength up to 980°C.
These specs include tolerances for hex sizes 18-57mm, with mandatory tests like tensile, hardness, and metallographic analysis for industrial compliance.
ISO 9001 certifications and mill test reports (MTRs) affirm export readiness from Mumbai to stringent markets.
Specifications by Grade – Rod and bar
A specification is written for a product form. The standards below are the ones that cover rod and bar; the plate, bar and tube specifications for these grades are different documents and are listed on their own pages.
| Grade | UNS | Rod and bar specification |
|---|---|---|
| Haynes 25 (L-605) | R30605 | AMS 5759 |
| Haynes 188 | R30188 | AMS 5772 |
| MP35N | R30035 | ASTM F562 / AMS 5758 / AMS 5844 / AMS 5845 |
| CoCrMo | R31537 | ASTM F1537 |
Equivalent Grades
Key equivalents: UNS R30605 (L605), Haynes 25, Udimet L605, DIN 2.4964, EN CoCr20W15Ni, offering consistent performance across aerospace and medical standards.
Stellite 6B (UNS R30016, AMS 5894) provides similar wear properties for abrasion-focused uses.
Product Forms and Availability
Available as hex bars 18-57mm (11/16″ to 2-3/4″) A/F, lengths up to 6m, in black, bright polished, or rough-turned finishes.
Square and flat variants support fabricators, with custom machining for OEM power and marine components.
Chemical Composition
| Element | L605 / R30605 (%) |
|---|---|
| Co | Balance |
| Cr | 19.0-21.0 |
| W | 14.0-16.0 |
| Ni | 9.0-11.0 |
| C | 0.05-0.15 |
| Fe | 3.0 max |
This formulation ensures solid-solution strengthening and carbide distribution for superior galling resistance.
Mechanical and Physical Properties
| Property | Value |
|---|---|
| Yield Strength (RT) | 310 MPa (45 ksi) |
| Tensile Strength | 862 MPa (125 ksi) |
| Elongation | 30% |
| Hardness | ≤277 HB |
| Density | 9.27 g/cm³ |
| Max Service Temp | 980°C |
Maintains strength to 816°C, outperforming nickel alloys in oxidation and sulfidation.
Industry Applications
Chemical Processing: Valves and pumps resist acidic corrosion and erosion where Hastelloy falls short at extreme temps.
Oil & Gas: Drill bits and bearings endure abrasion; cobalt market grows with deepwater demands.
Marine & Power Generation: Turbine parts and exhausts leverage oxidation resistance up to 1800°F.
Pharma uses biocompatible grades for implants; OEMs prefer for hot gas paths over nickel for stability.
Comparison with Common Grades
| Property | Cobalt L605 | Inconel 718 | Hastelloy X |
|---|---|---|---|
| Max Temp (°C) | 980 | 700 | 1200 |
| Wear Resistance | Excellent | Good | Fair |
| Oxidation Resist. | Superior | Good | Excellent |
| Cost for Wear Apps | Optimal | Higher | Higher |
Cobalt excels in wear/galling over nickel superalloys, ideal for frictional high-temp uses.
For complementary corrosion needs, explore our duplex steel hex bar range.
Quality and Compliance
Supplied with PMI, UT, tensile testing, and certificates of conformance (COC) per AMS/ASTM, ensuring NDT compliance for exports.
Electroslag remelted (ESR) process enhances cleanliness for critical power and aero apps.
Frequently Asked Questions
AMS 5759 for bars, AMS 5894 (Stellite), ASTM F90, DIN 2.4964, EN ISO 5832-5. These ensure high-temp strength, wear resistance for oil & gas, aero. Includes tolerances and testing protocols.
Yield 310 MPa, tensile 862 MPa, 30% elongation at RT; stable to 980°C. Hardness ≤277 HB, with superior galling resistance for valves, bearings in marine/power. (47 words)
Cobalt alloys like L605 offer better wear/impact resistance, stability to 900°C+ in vulcanizing/abrasive environments. Uniform carbides excel in friction; superior to nickel in galling-prone apps like drilling.
Hex 18-57mm A/F, up to 6m lengths; also square 18-47mm. Finishes: polished, turned; custom for OEMs, stocked in Mumbai for global supply. (46 words)
PMI, UT, tensile, hardness, microstructure per AMS; MTRs and COC provided. ESR melting for purity, vital for pharma implants and power turbines. (48 words)
Global Export Destinations
We ship worldwide from Mumbai. See every destination we export to on our export markets page.
Domestic Supply Network
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
Cobalt Alloy Hex Bars provide authoritative performance backed by rigorous standards and testing, instilling confidence for procurement in high-stakes industries.
How can we support your next high-wear application with precise specifications?