Aromatic Polyimide Enameled Constantan Round Wire – Grade 3 Thick
FilmThermal Class: 240 | Film Grade: 3 (thick) | Conductor: Constantan (Cu-Ni) | AWG: 22 – 30 | Max Service: 480°C (bare) |
Constantan wire – a copper‑nickel resistance alloy – is widely
recognized for its low temperature coefficient of resistance,
excellent solderability, and stable performance across a wide
temperature range (up to 480°C). When insulated with aromatic
polyimide and finished with a thick Grade 3 film, this material
becomes a high‑reliability solution for precision temperature
sensing and industrial electronics. CHINGCUNG now offers aromatic polyimide enameled constantan round wire with Grade 3 thick‑film insulation, specifically developed for T‑type thermocouples and other
demanding instrumentation applications. A stainless steel braided
shielded version is also available for enhanced mechanical
protection. 1. Product OverviewConductor Material | Constantan (Cu‑Ni alloy) | Insulation Type | Aromatic Polyimide | Thermal Class | 240 (max. continuous operating temperature 240°C) | Film Grade | Grade 3 (thick film) | Conductor Diameter Range | 0.255 mm – 0.642 mm (AWG 30 – 22) | Temperature Coefficient of Resistance | Low, stable across wide temperature range | Maximum Service Temperature | 480°C (bare wire) |
Key Feature: Grade 3 thick polyimide insulation significantly improves
dielectric strength and breakdown voltage compared to standard
thin‑film alternatives. 2. Technical Challenge & BreakthroughThe naturally high surface smoothness of constantan wire makes it
difficult for polyimide varnish to adhere uniformly. Through
repeated trials and formulation adjustments, our R&D team
successfully solved this adhesion challenge and achieved a Grade 3 thick polyimide coating with consistent film thickness and excellent adhesion strength. This breakthrough ensures: · Reliable insulation performance under thermal cycling · High dielectric strength for precision measurement circuits · Durable coating that resists peeling or cracking during winding 3. Specification TableNo. | Conductor Material | AWG | Conductor Dia. (mm) | Model Number | Max Overall Dia. (mm) | 1 | Constantan | 22 | 0.642 | QYKT-3/240-0.64 | 0.748 | 2 | Constantan | 24 | 0.511 | QYKT-3/240-0.51 | 0.597 | 3 | Constantan | 28 | 0.321 | QYKT-3/240-0.32 | 0.393 | 4 | Constantan | 30 | 0.255 | QYKT-3/240-0.255 | 0.320 |
Custom dimensions are available upon request. 4. Performance CharacteristicsThermal Class | 240°C (continuous) | Cut‑through Temperature | ≥ 450°C | Heat Shock Resistance | 260°C (IEC 60317 compliant) | Dielectric Strength | Significantly enhanced by Grade 3 film thickness | Thermal Aging Life at 200°C | > 20,000 hours (typical) | Radiation Resistance | Excellent | Chemical Resistance | Excellent (resistant to most solvents and oils) | Solderability | Bare constantan exhibits excellent solderability; polyimide coating
requires removal prior to soldering |
5. ApplicationsIndustry / Application | Description | T‑Type Thermocouples | Precision temperature measurement in industrial, laboratory, and
aerospace settings | Instrumentation | High‑stability sensing elements for meters and control systems | Industrial Electronics | Resistor elements, shunt circuits, and temperature compensation
networks | Aerospace & Defense | Sensors and actuators requiring high reliability in thermal cycling
environments | Medical Devices | Sterilizable temperature probes and diagnostic equipment | Research & Development | Calibration standards and experimental setups |
6. Quality StandardsAll CHINGCUNG constantan enameled wires are manufactured in ISO
9001 certified facilities and comply with the following
international standards: · IEC 60317‑7: 1997 – Enamelled round copper wire, Class 220 · IEC 60317‑46: 1997 – Enamelled round copper wire, Class 240 · GB/T 6109.6‑2008 – Enamelled round winding wires, Class 220 · GB/T 6109.22‑2008 – Enamelled round winding wires, Class 240 RoHS compliant – free from restricted hazardous substances. 7. Available OptionsShielded Version | Stainless steel braided wire over the enameled constantan for extra
abrasion and cut‑through protection | Film Grade | Grade 1 or Grade 2 available upon request (Grade 3 standard) | Conductor Diameter | Other AWG sizes or custom diameters available | Packaging | Spool types can be customized to meet winding machine requirements |
8. Why Choose CHINGCUNG?· Proven R&D capability – Over 10 years of experience in polyimide enameled wire
manufacturing · Process control – Strict quality management from raw material to finished coil · Flexible production – Small sample orders to bulk production (100+ tons monthly
capacity) · Traceability – Full documentation including test reports and material
certificates · Global service – Reliable logistics to North America, Europe, and Asia 9. Ordering InformationModel Number | QYKT-3/240-0.64 (example: AWG 22, Grade 3 thick film) | Minimum Order Quantity | Sample orders accepted | Lead Time | 2‑4 weeks depending on quantity | Shipping | Sea, air, or express freight available |
Need a sample or technical datasheet? Contact our team for free samples, detailed specifications, or
engineering consultation. Request a Sample View Products Tel: +86-13621982708 | Web: www.evmagnetwire.com | 
