High Temperature Resistance Pure Nickel Wire — Ni200 & Ni201 for Furnace, Thermocouple & Chemical Process

ISO9001 Factory Direct | Since 2002 | N4/N6/Ni200/Ni201 | 0.025–10mm | MP 1435–1446°C

Pure nickel wire from Changzhou DLX Alloy Co., Ltd. bridges a critical gap in the high-temperature materials spectrum — above the useful limit of copper and below the cost threshold of platinum. With a melting point of 1435–1446°C and reliable service to 315°C for Ni200 or well above for the low-carbon Ni201 variant, our pure nickel wire resists oxidation, maintains ductility through thermal cycling, and provides the thermal and electrical conductivity stability required in furnace heating elements, thermocouple conductors, chemical process sensors, and vacuum tube components. Manufactured from our own ingot through multi-pass precision drawing and controlled-atmosphere bright annealing, every spool is traceable to melt chemistry with full EN 10204 3.1 MTC documentation.

Pure nickel alloy is a high-quality metal material widely utilized for its outstanding physical and chemical properties. Comprising predominantly of high-purity nickel, this alloy typically contains minimal amounts of other alloying elements to enhance its performance. Pure nickel alloy boasts excellent conductivity, corrosion resistance, and high-temperature endurance, making it an ideal choice across various industrial sectors.
This alloy finds application in the electronics industry for manufacturing efficient electronic components such as connectors and wires, ensuring reliable electrical performance. In the chemical and petroleum industries, pure nickel alloy is extensively used in corrosion-resistant and high-temperature equipment, including chemical reactors and pipeline systems. In the aerospace sector, it is employed in the production of high-temperature alloys and critical components to withstand extreme environmental conditions.
Furthermore, pure nickel alloy plays a crucial role in light bulb manufacturing, artificial joints, precision instruments, and welding. Its exceptional mechanical properties and biocompatibility make it an ideal material for artificial joints, while in welding, pure nickel alloy provides excellent corrosion resistance and high-temperature stability.
Overall, the multifunctional properties of pure nickel alloy make it an indispensable material across various industries, offering reliable solutions for diverse applications.

Ni200 and Ni201 are chemically identical in nickel content — both ≥99.0% minimum. The difference is carbon: Ni200 allows up to 0.15% carbon. Ni201 limits carbon to ≤0.02%. At room temperature, this difference is metallurgically invisible. At 315°C and above, it determines whether the wire survives.

In Ni200 with 0.10% carbon, exposure to temperatures above 315°C causes carbon to diffuse to grain boundaries where it precipitates as graphite. These graphite particles are not just microstructural features — they are physical voids that decohere the grain boundaries. The wire loses ductility. Under thermal cycling, grain boundary cracks initiate at the graphite particles and propagate. After hundreds of hours above 400°C, Ni200 can become brittle enough to fracture under its own weight during handling — a phenomenon known as graphitization embrittlement.

Ni201, with carbon ≤0.02%, contains too little carbon to form continuous graphite films at grain boundaries. The wire retains its ductility after extended high-temperature exposure. It can be bent, coiled, and handled after thousands of hours at 500°C without fracturing. This is why Ni201 exists — not as a higher-purity upgrade, but as a fundamentally different metallurgical solution for sustained elevated-temperature service.

• The carbon specification that defines high-temperature capability — Ni200 and Ni201 look identical on a chemistry certificate except for one line: carbon. We do not treat Ni201 as "Ni200 with a different label." We control carbon from the melt — targeting ≤0.01% in every Ni201 ingot, well below the 0.02% specification limit. This is not over-engineering; it is the margin that prevents batch-to-batch variation from producing a heat that passes specification but fails after 1,000 hours at 500°C.
• Controlled-atmosphere bright annealed — no surface oxidation to remove before use — Wire drawn to 0.025 mm diameter has a surface-area-to-volume ratio that makes it extremely sensitive to oxidation during heat treatment. Our controlled-atmosphere (hydrogen or dissociated ammonia) annealing prevents surface oxidation at every intermediate anneal and at the final spool. The wire emerges bright and clean — no acid pickling required, no surface damage from oxide scale removal, no hydrogen embrittlement risk.
• 0.025 mm to 10 mm from one manufacturer — no process discontinuity — Drawing pure nickel from 10 mm rod down to 0.025 mm ultra-fine wire requires multiple intermediate anneals, progressively finer dies, and consistent lubrication. When the process is split across two manufacturers — one for coarse wire, another for fine — the annealing history and surface condition change at the handoff. Our integrated drawing line handles the full diameter range. The process history is continuous, and the wire properties are consistent across diameters.
• Thermal EMF stability — measured, not assumed — For thermocouple-grade nickel wire, the thermal EMF against a platinum reference is a critical performance parameter that is not captured on a standard chemistry certificate. We measure the thermal EMF of our thermocouple-grade nickel wire and certify the deviation from the standard reference table. Wire that does not meet the EMF tolerance is not sold as thermocouple-grade — regardless of its chemistry.
• Ingot-to-wire traceability — the documentation that heat treatment specifications demand — When a furnace manufacturer specifies Ni201 wire for a heating element lead that operates at 600°C, they need to prove to their customer that the wire chemistry — specifically the carbon content — meets the Ni201 specification. Our EN 10204 3.1 MTC traces the wire on every spool back to the original ingot chemistry. The documentation chain supports your product certification and your customer's audit requirements.
• Nickel-only facility — the wire has never touched anything else — Drawing pure nickel wire through dies that previously drew stainless steel leaves chromium and iron residue on the wire surface. At high temperature, this surface contamination diffuses into the nickel, locally altering the composition and potentially creating brittle intermetallic phases. Our drawing dies, lubricants, annealing furnaces, and spooling equipment are dedicated to nickel — because our entire facility is dedicated to nickel. The wire surface is as pure as the wire core.

Changzhou DLX Alloy Co., Ltd. has manufactured nickel wire since 2002. Over two decades, we have supplied pure nickel wire to furnace builders who stake their reputation on element life, to thermocouple manufacturers whose calibration certificates depend on wire consistency, and to vacuum tube fabricators who cannot tolerate parts-per-million contamination. Each of these customers taught us something about what matters in high-temperature nickel wire — and each lesson refined our process.

The critical lesson is this: at high temperature, the wire fails not because the nickel was defective, but because a process variable — carbon in the melt, oxygen in the annealing atmosphere, iron on the die surface — was slightly out of control. High-temperature performance is not a material property; it is a process control achievement. Our nickel-only facility, our in-house melting, our controlled-atmosphere annealing, and our full traceability from ingot to spool are the process controls that produce wire that survives at temperature — batch after batch, year after year.

• 12,000 m² nickel-only facility — melting, hot rolling, cold drawing, controlled-atmosphere annealing, spooling, and testing. No cross-material contamination. Every process surface is nickel-compatible.
• 0.025–10 mm full diameter range — one integrated drawing process. No handoff between coarse and fine wire manufacturers.
• All four pure nickel grades: N4, N6, Ni200, Ni201. Carbon-controlled Ni201 for sustained high-temperature service. Ultra-high-purity N4 for semiconductor and vacuum applications.
• ISO9001 with full ingot-to-spool traceability. SGS-accredited. Thermal EMF certification available for thermocouple-grade wire.

Chemistry certified from ingot through finished wire. Carbon content verified for every Ni201 heat — the single parameter that defines high-temperature suitability.

Carbon is the key differentiator for high-temperature applications. Ni201 with C ≤0.02% survives above 315°C without graphitization embrittlement. Ni200 below 315°C performs identically at lower cost. N4 and N6 provide progressively higher purity for applications where trace element control is critical.

Third-party verification by SGS, BV, or TÜV. Free sample available for high-temperature performance evaluation. Full documentation package with every shipment.

At 450°C, Ni200 will experience graphitization embrittlement. The wire will lose ductility progressively — after approximately 500–1,000 hours, it may become brittle enough to fracture under mechanical load or thermal cycling. If your wire is installed once and never disturbed — embedded in a furnace wall, for example — embrittlement may be acceptable. If the wire must survive handling, vibration, or thermal expansion/contraction cycles — which is nearly all real-world installations — Ni201 is required. The cost difference is approximately 10–20% for the wire. The cost of a field failure at 450°C is orders of magnitude higher.

We test every ingot for carbon by combustion analysis — the reference method for carbon determination in nickel. The result appears on the EN 10204 3.1 MTC that ships with your wire. If you require independent verification, we can supply a sample from your production lot for third-party carbon analysis at a laboratory of your choice. This is standard practice for customers in nuclear, aerospace, and vacuum furnace applications where carbon content is a safety-critical parameter.

Oxidation, not melting, is the limiting factor. Pure nickel oxidizes progressively in air above approximately 315°C — forming a green-black nickel oxide scale. The oxidation rate doubles roughly every 50–100°C increase. At 800°C, a 1 mm diameter wire will oxidize completely through in tens to hundreds of hours. For continuous service in air above 600°C, nickel-chromium alloys (NiCr) are preferred because the chromium forms a protective Cr₂O₃ scale that slows further oxidation. Pure nickel is best in reducing, neutral, or vacuum atmospheres at high temperature, or in air at temperatures below approximately 500°C where the oxidation rate is manageable for the intended service life. At DLX, we manufacture both pure nickel and NiCr wires — we can recommend the appropriate alloy for your temperature and atmosphere.

Yes. For Type K and Type T thermocouple extension wire, we can supply nickel wire with thermal EMF measured against a calibrated platinum reference at specified temperature points. The deviation from the IEC 60584 standard table is recorded on the certificate. Wire that does not meet the specified EMF tolerance is not shipped as thermocouple-grade. Specify your required EMF tolerance and temperature range when ordering.

N4 provides higher purity (Ni+Co ≥99.9% vs ≥99.0% for Ni201) with significantly lower iron (≤0.04% vs ≤0.4%). In semiconductor crystal growth furnaces operating at 800°C in vacuum, trace iron in the nickel wire can vaporize and deposit on the silicon wafer — creating defects that reduce yield. N4's 10× lower iron content proportionally reduces this contamination risk. N4 also has low carbon (≤0.01%) — providing the same high-temperature graphitization resistance as Ni201. For semiconductor applications where wafer contamination is the primary concern, N4 is specified. For general high-temperature applications where carbon embrittlement is the primary concern, Ni201 is the economical choice.