Quick answer: Hastelloy C-4 is a nickel-molybdenum-chromium alloy identified as UNS N06455 and W.Nr. 2.4610. Its low carbon, silicon and iron contents support good thermal stability and resistance to sensitization in welded heat-affected zones. A correct enquiry should still identify the product form, governing specification, dimensions, condition, inspection and documentation requirements.
Searches for “Hastelloy C4 datasheet,” “Alloy C-4,” “UNS N06455” and “Hastelloy C-4 supplier” often lead to the same material family, but the name alone is not a complete purchase description. This guide connects the common identifiers, published composition, product-form standards and RFQ details. For available forms and enquiry fields, start with the Hastelloy C-4 product page.
Hastelloy C-4 Identifiers
The identifiers below help match drawings, certificates and international enquiries. They point to the alloy family; they do not replace a current product specification or project-specific acceptance requirements.
| Identifier | Meaning | How to use it in an RFQ |
|---|---|---|
| Hastelloy C-4 / Alloy C-4 | Common trade and commercial names | Use with a neutral designation and product specification. |
| UNS N06455 | Unified Numbering System grade designation | Use as the primary neutral grade identifier. |
| W.Nr. 2.4610 | European material number | Add when the drawing or ERP uses Werkstoff numbers. |
| NiMo16Cr16Ti | European alloy-name cross-reference | Treat as a cross-reference, not the entire order description. |
Hastelloy C-4 Chemical Composition
Published manufacturer data describe C-4 as a nickel-base alloy with approximately 16% chromium and 16% molybdenum, together with tightly controlled carbon, silicon and iron. The values below are a practical identification summary. The governing material specification and its required revision control the acceptance limits.
| Element | Published nominal / typical level, wt.% | Procurement note |
|---|---|---|
| Nickel | Balance; approximately 65–66 | Principal base element. |
| Chromium | Approximately 16 | Contributes to resistance in oxidizing environments. |
| Molybdenum | Approximately 16 | Supports resistance in reducing media and localized attack. |
| Iron | Low; typically about 1, specification maximum may apply | Verify the certificate against the ordered document. |
| Carbon / Silicon | Intentionally low | Important to the alloy's thermal-stability concept; use specification limits for acceptance. |
| Titanium | Controlled minor addition | Confirm the full certified analysis rather than relying on a summary table. |
These values summarize published manufacturer data for grade identification. They are not standalone acceptance limits.
Why Thermal Stability Matters
C-4 was developed to reduce the formation of grain-boundary precipitates during exposure to intermediate temperatures. Published descriptions commonly discuss reduced precipitation tendency across roughly 650–1040°C. This helps explain why the alloy can retain corrosion resistance around welded heat-affected zones and may be suitable for some fabricated chemical-process equipment.
Important: 650–1040°C is a microstructural-stability discussion range, not a blanket allowable service-temperature range. Design temperature depends on environment, pressure, stress, product form, governing code, corrosion data and project approval. Do not copy that number directly into an equipment design or purchase order.
Product Forms and Common Specification Routes
The same UNS grade can be supplied under different standards because each document covers a product form. The table is a routing guide only; confirm scope, edition, dimensional standard and supplementary requirements before ordering.
| Product form | Common ASTM / ASME route | RFQ details to add |
|---|---|---|
| Plate, sheet and strip | ASTM B575 / ASME SB-575 | Form, thickness, width, length or coil details, tolerance, condition and surface. |
| Rod and bar | ASTM B574 / ASME SB-574 | Shape, diameter or section, length, tolerance, condition and test reports. |
| Seamless pipe and tube | ASTM B622 / ASME SB-622 | Pipe or tube, OD/NPS, wall or schedule, length, ends and inspection. |
| Welded pipe | ASTM B619 / ASME SB-619 | Size, wall, length, weld examination and supplementary tests. |
| Welded tube | ASTM B626 / ASME SB-626 | OD, wall, length, dimensional tolerance and examination class. |
| Fittings | ASTM B366 / ASME SB-366 | Fitting type, size, schedule/class, dimensions and construction route. |
| Welding consumables | ENiCrMo-7 / ERNiCrMo-7 routes may apply | Process, diameter, package, classification revision and procedure approval. |
Hastelloy C-4 vs C-276: Which Question Matters?
C-4 and C-276 are both nickel-chromium-molybdenum corrosion-resistant alloys, but one is not automatically a substitute for the other. C-4 is particularly associated with thermal stability and resistance to sensitization around welding. C-276 is a widely specified grade with a different chemistry and a broad application history in reducing and mixed corrosive environments. Selection should follow the actual medium and design conditions.
| Selection point | C-4 | C-276 |
|---|---|---|
| Key discussion | Thermal stability and welded heat-affected-zone behavior. | Broad established use across many aggressive chemical environments. |
| Can grade name decide? | No; medium, concentration, impurities, temperature and fabrication route matter. | No; the same design review is required. |
| Substitution | Requires engineering and specification approval. | Requires engineering and specification approval. |
Copy-Ready Hastelloy C-4 RFQ Checklist
| RFQ field | What to state | Why it matters |
|---|---|---|
| Grade | Hastelloy C-4 / UNS N06455 / W.Nr. 2.4610 | Removes ambiguity between similar C-family alloys. |
| Specification | Product-form standard and required revision | Defines the applicable production and acceptance route. |
| Product form and size | Plate/sheet/strip/bar/pipe/tube/fitting, dimensions and tolerances | Connects the alloy to a manufacturable item. |
| Condition and surface | Heat-treatment condition, finish and measurable acceptance | Prevents a generic grade name from deciding final condition. |
| Inspection and documents | Required tests, acceptance criteria, traceability and certificate format | Makes requested evidence auditable. |
| Service information | Medium, concentration, temperature, pressure, impurities and cleaning cycle when relevant | Supports material review without claiming universal suitability. |
| Commercial scope | Quantity, destination, required date, packing and quotation terms | Keeps technical and logistics scope together. |
Frequently Asked Questions
Is Hastelloy C-4 the same as UNS N06455?
They identify the same alloy family. UNS N06455 is the neutral UNS designation, while Hastelloy C-4 is a widely used trade name. The order must still add the product specification, revision, form and acceptance requirements.
Is 1040°C the maximum service temperature of C-4?
No. The frequently cited 650–1040°C range relates to precipitation behavior and thermal stability. An allowable service temperature must be evaluated for the actual environment, stress, pressure, code and product form.
Which standard should I quote for C-4 sheet, bar or pipe?
ASTM B575 is a common route for plate, sheet and strip; ASTM B574 for rod and bar; and ASTM B622 for seamless pipe and tube. Confirm that the selected edition includes UNS N06455 and matches the intended product form and project requirements.
What documents should accompany an enquiry?
State the required certificate type, chemical and mechanical test reports, heat/lot traceability, dimensional report and any project-specific inspection records. Do not assume that every document or third-party inspection is included unless it is written into the RFQ.
Conclusion
A useful Hastelloy C-4 datasheet enquiry starts with UNS N06455, then adds the correct product-form specification, dimensions, condition, inspection, documentation and service information. This is more reliable than treating a grade name, a typical chemistry table or a temperature range as a complete procurement requirement.
Prepare a Hastelloy C-4 Enquiry
Send the required grade, specification and revision, product form, dimensions, condition, quantity, destination, inspection and document requirements. SASA Alloy will review the requested scope against the specific enquiry.
Post time: Oct-26-2026