6J22 Karma Alloy Precision Resistance Foil
1. Product Overview
6J22 (Karma) is a nickel-chromium-aluminum-iron (NiCrAlFe) precision resistance alloy widely recognized as the material of choice for high-precision resistors and resistance strain gauges. Our 6J22 precision resistance foil is produced from high-purity raw materials through precision rolling and bright annealing, delivering uniform thickness, a clean bright surface and consistent electrical properties across the whole coil. Thickness ranges from 0.005 mm to 0.5 mm, with customized width available to match your etching, stamping or winding process.
2. Technical Specifications
Chemical composition: Ni balance; Cr 19.0-21.0%; Al 2.5-3.2%; Fe 2.0-3.0%; plus Mn, Si and trace elements.
Resistivity (20°C): 1.33 ± 0.07 μΩ·m
Temperature coefficient of resistance: ≤ ±20 × 10⁻⁶/°C
Thermal EMF vs copper (0-100°C): ≤ 2.5 μV/°C
Max. working temperature: ≤ 300 °C (250 °C recommended for precision resistors)
Elongation: > 7% Tensile strength: ≥ 780 N/mm²
Density: approx. 8.0-8.1 g/cm³
Thickness: 0.005 - 0.5 mm; Width: customized
Standard: JB/T 5328 / GB/T 15018, comparable to DIN and ASTM resistance alloy grades.
3. Features and Advantages
- Resistivity about three times higher than Manganin, enabling compact high-resistance elements.
- Very low temperature coefficient of resistance for stable performance over a wide temperature range.
- Low thermal EMF against copper, ideal for precision DC measurement circuits.
- Excellent long-term resistance stability and good oxidation resistance.
- Uniform gauge and clean surface, suitable for photochemical etching into foil resistors and strain gauge grids.
- Available in soft (annealed) or hard condition; good cold workability.
4. Applications
- Precision wire-wound resistors, standard resistors, slide resistors and current-sensing (sampling) resistors.
- Foil / thin-film resistors for high-precision electronic circuits.
- Resistance strain gauges and strain gauge foil for load, pressure, torque and acceleration sensors.
- Automotive electronics (e.g., BMS current sensing), industrial automation, test and measurement instruments.
- Medical devices, aerospace and defense electronics requiring high reliability.
- Chemical and industrial equipment.
5. Customization
Width, thickness tolerance, temper (soft / half-hard / hard), coil weight, inner and outer diameter can be customized according to your drawing or specification. MOQ 10 kg. Samples are available for evaluation.
6. Quality and Standards
Produced and tested in accordance with JB/T 5328 / GB/T 15018. Material certificates and third-party inspection reports are available upon request. A complete quality management system is implemented throughout production.
7. Packaging and Shipping
Coils wound on spools or paid off into cartons with moisture-proof film, packed on export wooden pallets. Shipping by sea (LCL/FCL), air freight, or international express for samples. Port of shipment: Shanghai, China.
8. Payment and Service
Payment terms: T/T, L/C at sight, D/P, Western Union, PayPal. We provide free technical consultation, sampling support and after-sales service. Please send your inquiry for the latest quotation and lead time.
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