Electrical Connections Thermal Stability Pure Nickel Wire — Ni200 & Ni201 for High-Temp Terminals, Crimps & Battery Tabs

Nickel-Only Factory | Since 2002 | Ni200/Ni201/N6 | 0.025–10mm | Oxidation-Resistant to 315°C+

A copper wire in a crimp terminal at 200°C fails not because the copper melts — it melts at 1085°C — but because the copper surface oxidizes. Copper oxide is a semiconductor. It grows as a film between the wire and the terminal wall, increasing contact resistance month by month until the connection overheats, oxidizes faster, and fails — a thermal runaway that begins with an oxide layer too thin to see. Pure nickel wire from Changzhou DLX Alloy Co., Ltd. solves this problem at the material level: nickel oxide grows orders of magnitude slower than copper oxide at any given temperature, is thinner, and — critically — remains electrically conductive enough that the connection resistance stays stable over years of elevated-temperature service. This is why nickel wire is specified for battery tabs, furnace terminal leads, high-temperature connectors, and any electrical joint that must survive where copper cannot. Full EN 10204 3.1 MTC traceability from ingot to spool on every shipment.

• Self-limiting oxide — the fundamental advantage of nickel over copper in hot connections — Copper oxide grows progressively: the oxide layer thickens with time and temperature, continuously increasing contact resistance until the connection fails. Nickel oxide grows to a limiting thickness — typically 50–100 nm at 300°C — and then essentially stops. Below this limiting thickness, the oxide film is thin enough that electron tunneling maintains conductivity across the interface. The connection resistance stabilizes at a slightly elevated value and remains there for the life of the connection. This is not a coating. This is a fundamental property of nickel — and it is why nickel wire is specified for hot electrical connections.
• Ni201 — the grade that extends thermal stability above 315°C — Ni200 wire serves reliably to 315°C — the temperature limit is set by graphitization embrittlement from the carbon content (≤0.15%), not by oxidation. Ni201 wire with carbon ≤0.02% extends the service temperature into the range where oxidation becomes the limiting factor — typically 500°C+ depending on atmosphere. For furnace terminal leads, heating element power connections, and high-temperature busbars, Ni201 is the specified grade. We control carbon at the melt — targeting ≤0.01% in every Ni201 ingot.
• Consistent resistivity — predictable IR drop across the connection wire — In a high-current connection, the wire itself contributes to the total circuit resistance. For a 1 meter length of 1.0 mm diameter nickel wire carrying 50 A, the wire resistance is approximately 0.12 Ω and the power dissipated in the wire is approximately 300 W — enough to raise the wire temperature significantly above ambient. If the wire resistivity varies by ±5% between spools, the temperature rise varies by ±5% — and a wire that runs 15°C hotter oxidizes faster and fails sooner. Our controlled annealing and consistent chemistry produce wire resistivity within ±3% across production lots.
• Bright annealed — the surface condition that determines initial contact resistance — The contact resistance of a freshly made crimp or screw terminal depends on the wire surface condition at the moment of assembly. Bright annealed wire has a smooth, oxide-free surface — the initial contact resistance is at the theoretical minimum for the contact geometry. Wire that was annealed in air and pickled has a microscopically roughened surface — the initial contact resistance is higher because the true contact area is smaller. Bright annealing is not cosmetic — it directly affects the electrical performance of every connection made with the wire.
• Monometallic joint compatibility — weld nickel wire to nickel tabs without dissimilar metal problems — In a battery pack, the nickel wire tab connects the cell terminal to the busbar. If the wire is nickel and the tab is nickel, the resistance weld creates a monometallic joint — no galvanic corrosion potential, no differential thermal expansion stress, no intermetallic phase formation at the weld interface. If the wire is copper and the tab is nickel, the Cu-Ni weld interface forms a brittle intermetallic layer that cracks under thermal cycling. The material compatibility is as important as the material properties.
• Nickel-only facility — the wire surface is nickel, not nickel with iron contamination from tooling — Iron particles embedded in the wire surface from steel drawing dies oxidize at temperature — forming resistive iron oxide at the contact interface. This increases the connection resistance in a way that is not predictable from the wire chemistry certificate. Our dies, lubricants, and annealing furnaces have processed only nickel since 2002. The wire surface is nickel — only nickel — and the contact resistance is what nickel metallurgy predicts, not what iron contamination degrades it to.

Changzhou DLX Alloy Co., Ltd. has drawn pure nickel wire for over two decades. Battery manufacturers buy our wire for interconnects because it welds cleanly and does not corrode. RTD sensor manufacturers buy our wire because the TCR is predictable and the resistance-per-meter is consistent. Relay manufacturers buy our wire because it maintains contact force through millions of cycles. Each of these customers taught us what matters for electrical-grade nickel wire — and the answer is always the same: consistency. Consistent chemistry produces consistent TCR. Consistent diameter produces consistent resistance per meter. Consistent annealing produces consistent mechanical properties. Consistent surface cleanliness produces consistent weld quality. Consistency is not achieved by inspection — it is achieved by controlling the process from ingot to spool. That is what a nickel-only facility with integrated melting, drawing, and annealing makes possible.

• 12,000 m² nickel-only facility — melting, hot rolling, cold drawing, hydrogen bright annealing, precision spooling. Every process surface is nickel-compatible. No cross-contamination from other metals that could alter electrical properties.
• N4, N6, Ni200, Ni201 — all four pure nickel grades. N4 for precision RTD and high-reliability electrical connections requiring minimum TCR variation. N6 for standard battery interconnects and relay components.
• 0.025–10 mm diameter range. Fine wire for RTD sensing elements. Medium wire for relay contact arms and connector springs. Heavy wire for high-current battery interconnects.
• ISO9001 with full ingot-to-spool traceability. SGS-accredited. TCR data and resistance-per-meter available on request. Thermal EMF certification for thermocouple extension wire.

Chemistry certified from ingot through finished wire. For electrical applications, Ni content, Fe content, and trace elements determine TCR, resistivity, and thermal EMF stability.