- Home
- Round Bars
- Cobalt /Stellite Alloy / Round Bars
- STELLITE GRADE 12 Round Bars
Stellite 12 Round Bars Supplier in Mumbai, India – UNS R30012
Nicorex Alloys is an ISO 9001/ISO 14001-certified supplier based in Mumbai, India. We supply batch-tested Stellite Grade 12 round bars manufactured with full compliance to AWS A5.21 standards.
Stellite Grade 12, also known as Cobalt Alloy 12 (UNS R30012, AWS A5.21 ERCoCr-B), is the intermediate Co-Cr-W wear-resistant alloy positioned between Stellite 6 (general-purpose) and Stellite 1 (extreme abrasion). Its typical composition is cobalt as the base with approximately 30% chromium, 8.5% tungsten, and 1.7% carbon. Its higher fraction of hard M7C3 carbides gives increased resistance to low-angle erosion, abrasion, and severe sliding wear while retaining reasonable impact and cavitation resistance. Tungsten at 7.5–9.5% provides hot hardness retention up to ~700°C. Stellite Grade 12 has a hardness of HRC 45–51 (435–590 HV) and a density of 8.53 g/cm³. It combines strong abrasion resistance with excellent galling resistance, both in self-mated conditions and when used with compatible cobalt-based alloys. Machinability is satisfactory using carbide-tipped tools, although grinding is generally preferred. Stellite 12 is non-magnetic (paramagnetic) and has a melting range of 1225–1280°C. Round bars are commonly available in diameters from 5 mm to 300 mm and lengths from 300 mm to 3000 mm, supplied in various forms including cast, HIPed, ground, centreless-ground, welding rod, and powder.
Core applications are industrial knives, saw tips, pump vanes, bearing bushes, glass mould plungers, engine valve hardfacing, and pinch rollers. Nicorex Alloys also supplies Stellite Grade 12 plates and welding consumables.
Cobalt Alloy UNS R30012 Bar Specifications
Key size and manufacturing details for Stellite Grade 12 (UNS R30012) round bars, including available diameters, production methods, and testing options:
| AWS | A5.21 ERCoCr-B (rod), ERCCoCr-B (wire); A5.13 ECoCr-B (electrode) |
|---|---|
| AMS / Military | AMS 7238 (P/M parts); MIL-C-24248 Comp II; SAE J775 (VF7) |
| Diameter | 5 mm to 300 mm |
| Length | 300 mm to 3000 mm (custom available) |
| Manufacturing | Casting (investment, centrifugal, sand), HIP, Powder Metallurgy |
| Conditions | As-Cast, HIPed, Ground, Centreless Ground |
| Tolerances | Standard or h6/h7 (ground bars) |
| Testing | PMI, Hardness (HRC), Chemical Analysis, UT, Dimensional |
| Certification | MTC per EN 10204 – 3.1 / 3.2 |
Chemical Composition of Stellite 12 Alloy
Stellite 12 alloy chemical composition, specification, covering cobalt, chromium, tungsten, carbon, and minor elements:
| Element | Cobalt (Co) | Chromium (Cr) | Tungsten (W) | Carbon (C) | Nickel (Ni) | Iron (Fe) | Silicon (Si) | Manganese (Mn) |
|---|---|---|---|---|---|---|---|---|
| Min | Balance (~52–58) | 27.0 | 7.5 | 1.4 | – | – | – | – |
| Max | Balance (~52–58) | 32.0 | 9.5 | 2.0 | 3.0 | 3.0 | 2.0 | 1.0 |
Chromium (27–32%) creates hard M7C3 carbides that improve abrasion resistance and form a Cr₂O₃ surface layer that protects against oxidation up to about 800°C. Tungsten at 7.5–9.5% (about twice as much as in Stellite 6) gives stronger strengthening of the metal and helps it stay hard up to around 700°C. Carbon at 1.4–2.0% produces a higher carbide volume while retaining more toughness than Grade 1.
Mechanical Properties of Stellite Alloy 12 Bar and Rod
Mechanical characteristics of Stellite Alloy 12 bars and rods, along with hardness, elongation and density, are listed below:
| Type | Hardness | UTS (typical) | Yield (typical) | Elongation | Density | Elastic Modulus |
|---|---|---|---|---|---|---|
| Cast | HRC 45–51 (435–590 HV) | ~740 MPa (107 ksi) | ~650 MPa (87 ksi) | <1% | 8.53 g/cm³ | ~226 GPa |
| HIPed | HRC 45–51 | ~1200 MPa (174 ksi) | ~900 MPa (130 ksi) | ~2% | 8.53 g/cm³ | ~208 GPa |
Hardness (HRC 45–51) is between Stellite 6 (36–45) and Stellite 1 (50–58). HIPed bars are much stronger, with UTS up to about 1200 MPa compared to about 740 MPa for cast bars, because they have finer, more even carbide distribution and fewer pores. They can be machined with carbide‑tipped tools, but grinding is still the best finishing method.
Physical Properties of Stellite Grade 12
Key physical characteristics of Stellite Grade 12 cobalt alloy (UNS R30012), including density, melting range, thermal expansion, and conductivity, are summarised:
| Property | Density | Melting Range | Thermal Expansion (20–100°C) | Thermal Conductivity (25°C) | Magnetic Behaviour |
|---|---|---|---|---|---|
| Value | 8.53 g/cm³ (0.308 lb/in³) | 1225–1280°C (2240–2335°F) | ~13.0 µm/m·°C | ~14.7 W/m·K | Non-magnetic (paramagnetic) |
Density (8.53 g/cm³) is between Stellite 6 (8.44) and Stellite 1 (8.69), consistent with intermediate tungsten content. They are non-magnetic despite cobalt being ferromagnetic.
Premium Industrial Materials
Get Stellite Grade 12 Round Bar
at Competitive Prices
Available Types of Stellite Grade 12 Round Bar
Nicorex Alloys stocks Stellite Grade 12 round bars in these forms:
Stellite 12 Cast Round Bar
UNS R30012 Ground Bar
Cobalt Alloy 12 Centreless-Ground Bar
Stellite 12 Alloy Rod
Wear Resistance & Corrosion Behaviour of Stellite 12 (Cobalt 12)
Stellite Grade 12 provides increased resistance to low-angle erosion, abrasion, and severe sliding wear compared to Stellite 6. A higher fraction of hard M7C3 carbides fills the gap where Grade 6 lacks sufficient abrasion resistance, but Grade 1’s extreme brittleness is unacceptable.
Tungsten at 7.5–9.5% gives hot-wear service to ~700°C, well above Stellite 6 (~500°C). Ideal for engine valve hardfacing, glass moulding at elevated temperatures, and rotor blade edges in steam turbines.
Chromium at 27–32% forms a Cr₂O₃ passive layer providing good corrosion resistance. It can undergo pitting-type corrosion in seawater and chloride environments and is suitable where combined wear and corrosion are present.
Galling resistance is excellent. Often self-mated or running against Stellite 6 or Stellite 1 for pump vanes, bearing bushes, control plates, and rolling couples.
Limitations: It has lower impact toughness than Stellite 6. Cast elongation <1% makes it crack-sensitive during hardfacing. For extreme abrasion at 760°C+, Stellite 1 is preferred. For cavitation-dominant service, Stellite 6 performs better.
Industries & Applications of Cobalt Alloy 12 Round Bar
Cobalt Alloy 12 round bars power long-life, high-temperature wear parts across wood, packaging, glass, metal, energy, oil, and textile industries.
-
Timber & Wood Processing: Saw tips for cutting hardwood, engineered lumber, and composites. Keeps a sharp edge and stays hard even at high cutting speeds, so tools last longer between re-sharpening than with Stellite 6.
-
Packaging & beverage industry: Used for control plates in bottling and canning lines. The material is corrosion‑resistant, safe for food contact, and non‑magnetic, so it can be used where it touches beverages.
-
Glass manufacturing: Used for narrow‑neck glass mould plungers. It stays hard at forming temperatures close to 700°C, helping maintain shape and surface quality during production. Excellent galling resistance prevents sticking during forming cycles.
-
Metal Processing & Forming: Pinch rollers in steel strip mills. Engine valve hardfacing for seats and faces that must withstand high exhaust temperatures.
-
Oil & Gas / Petrochemical: Pump vanes and bearing bushes in process pumps. Valve trim where moderate-to-severe abrasion with good corrosion resistance is needed.
-
Power Generation: Rotor blade edge hardfacing in steam turbines. Valve components in intermediate-temperature steam service approaching 700°C.
-
Paper, Plastics & Textiles: Industrial knives for cutting carpets, plastics, paper, and synthetic fibres. HRC 45–51 gives longer service life between re-grinds compared to Stellite 6 (HRC 36–45).
How to Order Stellite Grade 12 Round Bar from Nicorex Alloys
To order Stellite Grade 12 Round Bars, provide these 13 important details:
- Alloy Grade: Stellite Grade 12 / UNS R30012
- Product Form: Round bar, rod, cast bar
- Diameter (mm or inches)
- Length (standard or custom), Quantity (kg, pieces, or MT)
- Condition: As-cast, HIPed, Ground, Centreless-ground
- Surface Finish: As-cast, precision-ground, centreless-ground, polished
- Tolerance: Standard or h6/h7 & Certification: MTC 3.1 / 3.2 per EN 10204
- Specification: AMS 7238 (P/M), MIL-C-24248 Comp II, AWS A5.21 ERCoCr-B, or customer spec
- Testing: Hardness (HRC), chemical analysis, PMI, UT, dimensional
- Packaging & Delivery: Wooden case, export-grade, vacuum-sealed, Domestic India
Frequently Asked Questions
What is the Price of Stellite Grade 12 Round Bar in India?
The price depends on diameter, condition, specification, and cobalt market rates. HIPed material costs more than standard cast bar. Contact Nicorex Alloys for current pricing.
What is the Hardness of Stellite 12 Alloy Round Bar?
Hardness: HRC 45–51 (435–590 HV). A minimum hardness of HRC 42 is typically allowed to account for weld deposits. This hardness range lies between Stellite 6 (HRC 36–45) and Stellite 1 (HRC 50–58).
Can Stellite 12 be Machined?
Yes. Satisfactory results with carbide-tipped tools. Grinding remains preferred. Easier than Stellite 1 (grinding only) but harder than Stellite 6 (full carbide turning). EDM is also feasible.
What is the Maximum Service Temperature for Stellite Grade 12?
It works at temperatures up to about 700°C, which is higher than Stellite 6 (about 500°C), because it contains more tungsten. For service above 700°C, Stellite 1 is recommended.
Is Stellite Grade 12 Magnetic?
Stellite Grade 12 is Non-magnetic (paramagnetic). Cr and W additions suppress cobalt’s ferromagnetism. Suitable for non-magnetic wear components in beverage and instrumentation applications.
What Welding Processes Work with Stellite 12?
Stellite 12 can be welded by OAW, GTAW, GMAW, SMAW, PTA, HVOF, and laser cladding using AWS A5.21 ERCoCr-B, ERCCoCr-B, or A5.13 ECoCr-B fillers, but it is more crack-sensitive than Stellite 6, so a 200–400°C preheat is recommended.
Why Choose Stellite 12 over Stellite 6 or Stellite 1?
Choose Stellite 12 when Grade 6 lacks sufficient abrasion resistance or hot hardness, but Grade 1’s brittleness is unacceptable. It is the best middle-choice material for cutting tools, saw tips, glass mould plungers, and other high-temperature wear parts.