4J36 Invar Alloy Strip Low Expansion Iron-Nickel Strip ASTM F1684 for Glass Sealing and Precision Components
Product Attributes
| Attribute |
Value |
| Tensile Strength |
≥ 450 MPa |
| Yield Strength (0.2%) |
≥ 270 MPa |
| Elongation |
≥ 30% |
| Hardness |
≤ 160 HV |
| Density |
~8.1 g/cm³ |
| Thermal Expansion (20–100°C) |
~1.2 × 10⁻⁶ /°C |
| Max Service Temp |
~300°C (572°F) |
| Country of Origin |
China (OEM and custom logo available) |
Product Description
4J36 strip, also known as Invar 36, is a low-expansion iron-nickel alloy composed of approximately 36% nickel and 64% iron. It exhibits an extremely low coefficient of thermal expansion in the temperature range of −60°C to 250°C, making it highly suitable for precision instruments and sealing applications.
This strip alloy conforms to ASTM F1684 and is widely used in manufacturing electronic supports, glass-to-metal seals, thermostat components, aerospace instruments, and precision optical systems. Its dimensional stability and excellent mechanical properties under thermal stress make it a preferred material for applications requiring minimal deformation under temperature changes.
Key Features
- Exceptionally low thermal expansion from cryogenic to ~250°C
- Excellent dimensional stability and formability
- Good machinability and weldability
- High structural integrity in vacuum and sealed environments
- Compatible with glass and ceramic sealing processes
- Available in precision thicknesses with bright surface finish
Typical Applications
- Glass-to-metal sealed enclosures and headers
- Shadow masks and structural parts for CRTs and sensors
- Aerospace and aviation instrumentation
- Bimetal thermostatic components
- Electronic scale frames and supports
- Precision molds and measurement tools
- Laser/optical mounting brackets
Chemical Composition (%)
| Element |
Typical Content (%) |
| Nickel (Ni) |
35.0 - 37.0 |
| Carbon (C) |
≤ 0.05 |
| Manganese (Mn) |
0.30 - 0.60 |
| Silicon (Si) |
≤ 0.30 |
| Phosphorus (P) |
≤ 0.020 |
| Sulfur (S) |
≤ 0.020 |
| Iron (Fe) |
Balance |
Mechanical Properties (Annealed Condition)
| Property |
Typical Value |
| Tensile Strength |
≥ 450 MPa |
| Yield Strength (0.2%) |
≥ 270 MPa |
| Elongation |
≥ 30% |
| Hardness |
≤ 160 HV |
| Density |
~8.1 g/cm³ |
| Thermal Expansion (20-100°C) |
~1.2 × 10⁻⁶ /°C |
| Max Service Temp |
~300°C (572°F) |
Available Specifications
| Item |
Details |
| Thickness Range |
0.05 mm - 2.0 mm |
| Width Range |
3 mm - 300 mm |
| Form |
Strip in coil, sheet cut-to-length |
| Surface Finish |
Bright, cold-rolled, deburred |
| Standards |
ASTM F1684, GB/T 13240, DIN 17745 |
| Condition |
Annealed, stress-relieved |
| Packaging |
Plastic wrap + carton or wooden box |
| Certification |
ISO 9001, ROHS, EN 10204 3.1 |
| Country of Origin |
China (OEM and custom logo available) |
Packaging & Shipping
- Packaging: Plastic spools, vacuum bags, anti-rust wrapping, and customized labels upon request
- Shipping Methods: Air freight, sea freight, express delivery
- Lead Time: 7-15 working days based on order quantity