When a petrochemical client endured repeated element failures and scaling in a high-temperature furnace, the answer was a custom batch of NiCr 70:30 Round Bars. Engineered for industrial reliability, these bars proved their value with the highest oxidation and scaling resistance in the nichrome family, making them essential for chemical, marine, oil & gas, pharma, and power sector engineers seeking longer lifecycle and reduced downtime.
Table of Contents:
NiCr 70:30 (UNS N06003, W.Nr. 2.4658) is an austenitic nickel-chromium resistance heating alloy of roughly 70% nickel and 30% chromium, with iron held low and small silicon and manganese additions. The chromium content is the highest of the nichrome grades, which is what gives it the family's best resistance to scaling and to oxidising furnace atmospheres. It is specified for heating elements, furnace fixtures, radiant tube supports and resistor components, and machines and welds much as the other nichromes do. Composition limits and physical constants are tabulated below.
Bars and rods are available from 6mm to 120mm diameter, in polished, hot-rolled, and custom-fabricated finishes, supporting maintenance, OEM, and rapid repair projects. Every batch is traceable and supplied with mill certificates per ASTM B344. Hardware stores and OEMs rely on these for element terminals, furnace hangers and supports, machined resistor parts, and demanding hot-zone hardware.
While NiCr 70:30 is most often chosen for the scaling resistance its chromium content buys, it is equally suited to energy, pharma, and power plant service. Suppliers also stock NiCr 70:30 Round Bars for fast delivery and certified quality for engineers, procurement leads, and industrial supply chains.
High-quality NiCr 70:30 Round Bars ready for industrial use.
Specification Overview
| Grade | NiCr 70:30 (UNS N06003, W.Nr. 2.4658) |
|---|---|
| Standards | ASTM B344 (rod and bar) |
| Diameter Range | 6mm–120mm |
| Length | 100mm–3660mm (up to 6 meters custom) |
| Finish | Polished, hot-rolled, custom machine-cut |
| Delivery | Export pack, full MTC, batch/lot traceability |
Equivalent Grades & Standards
| Property | Value |
|---|---|
| UNS number | N06003 |
| Werkstoff / EN number | 2.4658 |
| EN designation | NiCr 70 30 |
| Density | 8.1 g/cm3 |
| Melting range | 1400 °C |
| Electrical resistivity (20 °C - per DIN 17470) | 119 µΩ·cm |
| Electrical resistivity (20 °C - per ASTM B 344) | 116 µΩ·cm |
| Thermal conductivity | 13.8 W/m·K |
| Specific heat (20 °C) | 420 J/kg·K |
| Coefficient of expansion (200 °C) | 13.5 µm/m·°C |
| Modulus of elasticity | 200 kN/mm² |
| Maximum operating temperature in air | 1250 °C (sheet prints this as approximate) |
| Rod and bar specification | ASTM B344 |
Identifiers and physical constants for Nichrome 70/30. A dash means no such designation is published for this grade.
Stock & Product Availability
NiCr 70:30 Round Bars are reliably stocked in all common diameters and lengths for urgent delivery supporting chemical, marine, pharma, and oil & gas plant operations needing fast turnaround with global compliance.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Iron (Fe) | — | 1 |
| Chromium (Cr) | 29 | 31 |
| Nickel (Ni) | — | Balance |
| Carbon (C) | — | 0.07 |
| Manganese (Mn) | — | 1.0 |
| Silicon (Si) | 1 | 1.5 |
| Copper (Cu) | — | 0.5 |
| Aluminium (Al) | — | 0.2 |
| Others | 0.01 | 0.04 |
Composition limits for Nichrome 70/30. These are specification limits for the grade, not measured values for a lot; the mill test certificate supplied with your order states the actual analysis.
Mechanical & Physical Properties
| Property | Typical Value |
|---|---|
| Tensile Strength (MPa) | 345 |
| Yield Strength (MPa) | 140 |
| Elongation (%) | 30 % |
| Temperature Range (°C) | 927–1038 |
Applications & Benefits
- Chemical: process heaters, vaporizer rods, furnace fixtures, calciner internals
- Marine: incinerator element supports, exhaust-side resistors, hot-gas hardware
- Oil & Gas: heater-treater elements, thermal process supports, autoclave cores
- Pharma: sterilizer and depyrogenation-oven elements, temperature control grids
- Power: cartridge and immersion heater cores, high-temperature process lines
- Fabrication/Supply: element terminals, machined resistor parts, urgent custom bars for hardware shops
FAQ & Search Trends
Global Export Destinations
We ship worldwide from Mumbai. See every destination we export to on our export markets page.
Domestic Supply Network Across India
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
NiCr 70:30 Round Bars provide proven scaling resistance, weldability, and compliance for mission-critical chemical, marine, pharma, oil & gas, and power sectors. Are your assets protected with globally certified heating alloys that deliver longer life and lower maintenance?