Precision Instrument Welding Alloy Pure Nickel Wire

Nickel-Only Factory | Since 2002 | N4/N6/Ni200/Ni201 | ±0.01mm Tolerance | Free Sample MOQ 5kg

When a thermocouple junction is welded under a microscope at 20* magnification, the wire that forms the bead must melt predictably — not spit, not spatter, not oxidize, and not introduce contamination that shifts the thermoelectric calibration by half a degree. When a vacuum tube grid is resistance-welded to its support frame, the wire must fuse cleanly — no porosity from dissolved gases, no brittle intermetallic from surface contamination, no carbon boil from residual lubricant. Pure nickel wire from Changzhou DLX Alloy Co., Ltd. is manufactured for these welds — drawn from our own ingot through multi-pass precision reduction, bright annealed in hydrogen to eliminate surface oxide without pickling, and spooled with controlled tension to deliver consistent feed into automated micro-welding systems. Full EN 10204 3.1 MTC traceability from ingot to spool on every shipment.

Pure nickel is inherently weldable. It has a wide solidification range, good hot ductility, and does not form brittle intermetallic phases during solidification. The problems that cause nickel wire welds to fail are not intrinsic to nickel — they are introduced during wire manufacturing.

• Controlled from the melt for weldability — not selected from standard production — Carbon causes weld porosity. Sulfur causes hot cracking. Iron and copper segregate during solidification and shift thermoelectric calibration. At DLX, we control these elements at the ingot stage — targeting the lower end of the specification range for welding-grade wire. This is not "standard wire that happens to weld well." It is wire manufactured with weldability as the primary performance requirement.
• Bright annealed in hydrogen — the surface that enters your weld is the surface we created in the furnace — Wire annealed in air develops nickel oxide that must be removed by acid pickling. Pickled wire has a microscopically etched surface — pits, crevices, and residual acid that vaporize in the arc. Wire bright annealed in hydrogen has no oxide, requires no pickling, and enters your welding process with a clean, smooth, chemically homogeneous nickel surface. The difference is visible in the weld — bright annealed wire produces a brighter, cleaner, more consistent weld bead.
• ±0.01 mm diameter tolerance — because automated welding systems count on it — A micro-TIG welding system feeds wire at a programmed rate based on nominal diameter. If the actual diameter varies, the melt volume varies — and the weld bead size varies. For a 0.25 mm wire, ±0.01 mm tolerance means cross-sectional area is controlled within ±8% — tight enough that the variation in weld bead size is imperceptible under 10* magnification. For automated production lines welding thousands of identical joints, this consistency is the difference between zero-rework and 5% rework.
• Clean surface — verified by water break test on every spool — Drawing lubricant residue on the wire surface is invisible to the naked eye but catastrophic in the weld: it vaporizes, creates porosity, contaminates the shielding gas, and deposits carbon on the weld surface. Our multi-stage cleaning after the final drawing pass removes all lubricant residue. The water break test — a continuous unbroken film of deionized water on the wire surface — confirms cleanliness. If the film breaks, the spool is re-cleaned. We do not ship wire that fails this test.
• Full ingot-to-spool traceability — the documentation that supports your weld procedure qualification — When you qualify a welding procedure for a precision instrument, you specify the wire grade, diameter, and supplier. If the wire changes — a different heat, a different chemistry — the weld procedure must be re-qualified. Our EN 10204 3.1 MTC traces every spool to a specific ingot with a specific chemistry. You know exactly what you are welding — and you can prove it to your customer.
• Nickel-only facility — the wire has never been contaminated by another alloy — Drawing pure nickel wire through dies that also draw stainless steel, copper, or resistance alloys contaminates the nickel surface with foreign metal particles. In a weld, these particles create localized composition variations — potential corrosion sites, potential brittle phases, potential EMF shifts. Our dies, lubricants, and furnaces have processed only nickel since 2002. The wire is nickel — and only nickel — from ingot to spool.

Changzhou DLX Alloy Co., Ltd. has drawn pure nickel wire for two decades. Some of that wire goes to welding — and welding customers ask questions that other customers do not. They ask about carbon content because carbon causes porosity. They ask about surface cleanliness because residue causes spatter. They ask about diameter tolerance because automated feed systems count on consistent cross-section. They ask about traceability because a weld procedure qualification is only as valid as the wire it was qualified with.

These questions taught us what matters for welding wire — and our process reflects the answers. Carbon is controlled at the melt and verified by combustion analysis. Surface cleanliness is verified by water break test on every spool — not sampled, not assumed. Diameter is monitored in-line by laser micrometer and verified at final inspection. Traceability is absolute — every spool linked to an ingot chemistry certificate by heat number.

• 12,000 m² nickel-only facility — melting, hot rolling, cold drawing, hydrogen bright annealing, precision spooling, and testing. Every process surface is nickel-compatible. No cross-contamination from other alloys.
• N4, N6, Ni200, Ni201 — all four pure nickel grades. N4 for ultra-low-carbon, ultra-low-trace-element welding. N6 for general precision instrument welding. Ni201 for applications where post-weld service exceeds 315°C.
• 0.025–10 mm diameter range. One integrated process — no handoff between coarse and fine wire manufacturers that changes the annealing history or surface condition.
• ISO9001 with full ingot-to-spool traceability. SGS-accredited. Water break test and diameter record on every spool. Thermal EMF certification for thermocouple welding-grade wire.

Chemistry certified from ingot through finished wire. For welding applications, carbon, sulfur, iron, and copper are the critical elements that determine weld quality — not just corrosion resistance.

⬤ = critical for weld quality. Carbon >0.02% causes CO porosity. Sulfur >0.005% causes hot cracking. Iron and copper segregate during solidification — altering the weld bead composition relative to the wire. For the cleanest, most predictable welds — thermocouple junctions, vacuum tube grids, medical sensor seals — N4 is recommended. N6 provides excellent weldability for general precision instrument applications. Ni201 for welding followed by elevated-temperature service above 315°C.

Third-party verification by SGS, BV, or TÜV. Free 5 kg sample for welding procedure qualification. Complete documentation package with chemistry cert, diameter record, and water break test certification.

Our standard nickel wire meets the chemistry specification for its grade and is suitable for general applications. Our welding-grade wire is the same material — but with tighter controls on the parameters that affect weld quality: carbon is targeted at the lower end of the specification range (≤0.01% for N4, ≤0.02% for Ni201), sulfur is minimized, every spool is water-break tested for surface cleanliness, diameter is verified by laser micrometer, and the spool is wound with controlled tension for consistent automated feed. The wire is the same nickel — the process control is what makes it welding-grade.

Yes — if you order bright annealed wire and keep it in its sealed packaging until use. The hydrogen bright annealing process produces a clean nickel surface free of oxide and drawing lubricant. The vacuum-sealed packaging preserves that surface. Wire taken directly from the sealed spool and placed into your welding wire feeder requires no pre-cleaning — the surface is as clean as it was when it left our hydrogen annealing furnace. If the spool has been opened and exposed to shop air for more than 48 hours, we recommend a quick solvent wipe before welding.

This depends on the thermocouple type and the accuracy requirement. For Type K (chromel-alumel) extension wire — where the nickel wire is the positive conductor — N6 is the standard choice. For premium aerospace or laboratory-grade thermocouples where calibration drift at the welded junction must be minimized over thousands of thermal cycles, N4 is recommended — the minimal impurity content (Fe ≤0.04%, Cu ≤0.015%) means minimal composition change at the weld bead during solidification, and therefore minimal EMF shift at the junction. Provide your thermocouple type and accuracy class — we will confirm the appropriate grade.

We can provide starting parameter ranges for common welding processes based on wire diameter: TIG current, arc voltage, travel speed, shielding gas type and flow rate. However, the optimal parameters depend on your specific joint geometry, fixturing, and weld quality requirements. We recommend developing your welding procedure using our trial sample — start with the parameters we suggest, then optimize for your specific application. Our technical team is available to review your weld cross-sections and discuss parameter adjustments.

Erratic feed is almost always caused by spool winding quality — crossed turns, inconsistent tension, or a snag. Our precision layer-winding with controlled back-tension eliminates these issues. If you experience feed problems with our wire, send us a video of the feed behavior and the spool label — we will trace the spool to its winding record and identify the root cause. In the rare event of a winding defect, we replace the spool at no charge and implement corrective action in our winding process.