EN
Economical Cr20Ni30 NiCr Electric Resistance Wire (0.4mm) for Open Coil Heating Elements
High-efficiency Cr20Ni30 (Nickel-Chromium 30/20 / Nikrothal 30 equivalent) electric resistance alloy wire, engineered as a cost-effective alternative for medium-to-high temperature applications up to 1050°C (1922°F). Featuring 0.40mm precision diameter, bright-annealed finish, and consistent electrical resistivity, this wire delivers rapid heat-up and dependable thermal cycling for open-coil air heaters, mica frame elements, and industrial drying appliances.
- Overview
- Technical Specifications
- Key Engineering Features
- Industrial Applications
- Product FAQ
- Recommended Products
Product Overview: Cr20Ni30 Resistance Alloy Wire for Cost-Effective Open Coil Heating
Cr20Ni30 is an economical nickel-chromium-iron electric resistance alloy formulated for applications where maximum furnace temperatures do not exceed 1050°C (1922°F), offering substantial material cost savings over high-nickel Cr20Ni80 grades while maintaining excellent mechanical ductility and anti-sagging properties.
Manufactured with precision diamond dies and continuous bright annealing, this 0.40mm resistance wire ensures uniform cross-sectional tolerance (±0.01mm) and clean surface finish. When energized in convective air streams, it rapidly establishes a protective oxide scale that resists surface flaking, providing high thermal efficiency and extended service life in open coil suspended heaters, ceramic rack elements, and household convective heating appliances.
Technical Specifications
| Property / Parameter | Metric Value | Imperial / Standard Value | Remarks / Tolerance |
|---|---|---|---|
| Alloy Grade | Cr20Ni30 (30% Ni, 20% Cr, Bal. Fe) | NiCr 30/20 / Nikrothal 30 Eq. | Economical Ni-Cr Alloy Matrix |
| Wire Diameter | 0.40 mm | 0.0157 inch (26 AWG) | ±0.01 mm Precision Tolerance |
| Max. Continuous Temp | 1050°C | 1922°F | In Air / Convective Gas Flow |
| Electrical Resistivity (20°C) | 1.04 ± 0.05 μΩ·m | 626 Ω·cmf | High Batch Ohmic Uniformity |
| Density | 7.90 g/cm³ | 0.285 lb/in³ | Lightweight Fe-Ni-Cr System |
| Melting Point | 1390°C | 2534°F | Solidus / Liquidus Transition |
| Tensile Strength (Annealed) | 600 – 750 MPa | 87 – 109 ksi | Soft Annealed Temper |
| Elongation | ≥ 20% | ≥ 20% | High Ductility for Tight Coiling |
| Magnetic Properties | Non-Magnetic to Weakly Magnetic | Magnetic at Room Temp | Curtailed by Operating Temp |
| Delivery State | Bright Annealed | Soft Condition (M State) | Clean, Smooth, Oxide-Free |
Key Engineering Features of 0.4mm Cr20Ni30 Open Coil Resistance Wire
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High Cost-to-Performance Ratio for 1050°C Applications
Optimized 30% Nickel formulation delivers reliable oxidation resistance and thermal expansion stability at a significantly lower raw material cost compared to 80/20 NiCr grades. -
Rapid Heat-Up and High Convective Thermal Efficiency
The 0.40mm fine gauge provides a high surface-area-to-volume ratio, facilitating fast thermal response and uniform radiant-convective heat transfer across open-air coils. -
Superior Ductility for High-Speed Element Coiling
Supplied in fully bright-annealed soft temper with elongation ≥ 20%, permitting high-speed automated winding onto ceramic mandrels and mica cross-frames without wire breakage or micro-cracks. -
Consistent Resistance and Low Risk of Element Sagging
Maintains high hot strength and structural integrity below 1050°C, minimizing coil distortion, turn-to-turn short-circuiting, and premature element burnout in horizontal or vertical suspension.
Industrial Applications: Where 0.4mm Cr20Ni30 Heating Wire Excels
- Open Coil Air Duct Heaters: Suspended spiral heating coils for HVAC duct heaters, forced-air space heaters, and industrial heat guns.
- Mica & Ceramic Frame Elements: Precision wound resistance heating grids for hair dryers, convection toasters, shrink tunnels, and laminating equipment.
- Industrial Drying & Dehumidifying Equipment: Open-wire heating banks for textile drying ovens, grain dryers, and paint curing tunnels.
- Defrost & Low-Temperature Resistor Units: Defrosting heater assemblies, laboratory drying cabinets, and wire-wound load banks.
Frequently Asked Questions (FAQ) for Cr20Ni30 Open Coil Heating Wire
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Q1: What are the main advantages of choosing Cr20Ni30 over Cr20Ni80 for open coil elements?
A: For heating applications operating below 1050°C (such as convective air heaters, mica frame elements, and hair dryers), Cr20Ni30 provides virtually identical thermal performance and workability to Cr20Ni80 at a substantially reduced unit cost due to lower nickel content. -
Q2: Does Cr20Ni30 wire sag easily when suspended horizontally in open coil racks?
A: When operated within its rated temperature limit of 1050°C, Cr20Ni30 maintains excellent hot tensile strength and sag resistance—far superior to FeCrAl alloys of comparable gauge, which tend to coarsen and sag after initial heating. -
Q3: What spooling options and diameter tolerances are available for 0.40mm wire?
A: Our 0.40mm wire is manufactured to a precision tolerance of ±0.01mm and supplied on standard DIN 100 (1.0 kg), DIN 125 (1.5 kg), or DIN 160 (3.5 kg) spools, vacuum-sealed with desiccant packaging to prevent oxidation during sea transit. -
Q4: What is the MOQ, sample policy, and delivery lead time?
A: Standard MOQ is 5 kg per batch, with 0.5 kg free evaluation samples available upon request. Regular spool orders ship within 7–10 working days complete with EN 10204 3.1 Mill Test Certificates (chemical composition and resistivity testing).
