Invar 36 Alloy Plate
Product Short Description
Invar 36 Alloy Plate, also known as Alloy 36, UNS K93603, FeNi36 and 36Ni-Fe low expansion alloy, is a nickel-iron controlled expansion alloy with an extremely low coefficient of thermal expansion around room temperature. It is widely used in precision instruments, optical equipment, molds, aerospace fixtures, measuring devices and components requiring high dimensional stability under temperature changes.
SASA ALLOY supplies Invar 36 / Alloy 36 / UNS K93603 plate in customized thickness, width, length and surface condition. Products can be supplied with chemical composition analysis, mechanical testing, dimensional inspection, PMI testing, surface inspection, EN 10204 3.1 material certificate and full heat number traceability according to project requirements.
- Product Name: Invar 36 Alloy Plate
- Material Grade: Invar 36 / Alloy 36 / UNS K93603 / FeNi36
- Product Type: Controlled Expansion Alloy Plate
- Main Feature: Very low thermal expansion and excellent dimensional stability
- Applications: Precision instruments, optical devices, aerospace fixtures, molds and tooling
Product Parameters
| Item | Specification |
|---|---|
| Product Name | Invar 36 Alloy Plate |
| Material Grade | Invar 36 / Alloy 36 / UNS K93603 / FeNi36 / 36Ni-Fe |
| Material Type | Nickel-Iron Controlled Expansion Alloy |
| Product Form | Plate, Sheet, Strip, Flat Bar, Cut Plate, Machined Plate |
| Thickness | 0.5 mm – 100 mm or customized |
| Width | 100 mm – 2000 mm or customized |
| Length | 500 mm – 6000 mm or cut to size |
| Surface Condition | Hot Rolled, Cold Rolled, Pickled, Polished, Ground, Machined |
| Standard | ASTM, UNS, AMS, EN, DIN, JIS, GB or customer specification |
| Inspection | Chemical Analysis, Mechanical Test, PMI Test, Dimensional Inspection, Surface Inspection |
| Certificate | EN 10204 3.1 Material Certificate available |
| Processing Service | Cutting, Shearing, Grinding, CNC Machining, Custom Size Processing |
Chemical Composition
The chemical composition of Invar 36 alloy plate is controlled to achieve stable low thermal expansion performance. The following composition is for general reference only. Final values should be confirmed according to the applicable standard and mill test certificate.
| Element | Ni | Fe | C | Mn | Si | P | S | Co | Cr | Cu |
|---|---|---|---|---|---|---|---|---|---|---|
| Content % | 35.0 – 37.0 | Balance | ≤0.05 | ≤0.60 | ≤0.35 | ≤0.020 | ≤0.020 | ≤0.50 | ≤0.25 | ≤0.50 |
Mechanical Properties
Mechanical properties of Invar 36 alloy plate may vary depending on thickness, heat treatment condition, cold working ratio and applicable standard. SASA ALLOY can supply test reports according to customer requirements.
| Condition | Tensile Strength | Yield Strength | Elongation | Hardness | Density |
|---|---|---|---|---|---|
| Annealed / Typical | 450 – 600 MPa | 240 – 300 MPa | 25% min | According to condition | Approx. 8.1 g/cm³ |
| Cold Worked / Custom | According to order | According to order | According to order | According to order | Approx. 8.1 g/cm³ |
Note: For precision applications, coefficient of thermal expansion, dimensional stability and heat treatment condition are often more important than conventional strength values.
Common Size Table
| Thickness | Width | Length | Surface | Availability |
|---|---|---|---|---|
| 0.5 – 3.0 mm | 100 – 1000 mm | 500 – 3000 mm | Cold Rolled / Pickled | Stock / Production |
| 3.0 – 10 mm | 300 – 1500 mm | 1000 – 4000 mm | Hot Rolled / Pickled | Stock / Production |
| 10 – 30 mm | 500 – 2000 mm | 1000 – 6000 mm | Hot Rolled / Ground | Production |
| 30 – 100 mm | According to order | According to order | Machined / Ground | Made to Order |
Different Specifications Comparison
| Type | Thickness Range | Surface Condition | Typical Use |
|---|---|---|---|
| Invar 36 Sheet | 0.5 – 6 mm | Cold Rolled / Pickled / Polished | Precision parts, electronic components, small tooling parts |
| Invar 36 Plate | 6 – 100 mm | Hot Rolled / Ground / Machined | Molds, aerospace fixtures, optical platforms, measuring equipment |
| Invar 36 Cut Plate | Customized | Cut / Ground / Machined | Custom machining blanks and precision components |
| Invar 36 Precision Plate | According to drawing | Ground / CNC Machined | High precision tooling, optical and instrument components |
Equivalent Standards and International Names
Invar 36 alloy plate is known by different names in international markets. Customers may search for Invar 36, Alloy 36, UNS K93603, FeNi36 or low expansion alloy plate.
| Country / Standard | Common Name | Equivalent Grade |
|---|---|---|
| USA / UNS | UNS K93603 | Invar 36 |
| Commercial Name | Alloy 36 | Invar 36 |
| Fe-Ni System | FeNi36 | 36Ni-Fe Low Expansion Alloy |
| Europe | 1.3912 | FeNi36 |
| China | 4J36 | Invar 36 Equivalent |
Production Process Flow
The production process of Invar 36 alloy plate requires strict control of chemical composition, melting quality, rolling condition, heat treatment and dimensional accuracy to ensure stable low expansion performance.
| Process Step | Description | Quality Control Point |
|---|---|---|
| Raw Material Selection | Select qualified nickel and iron raw materials | Raw material certificate and traceability |
| Melting | Control alloy composition and impurity elements | Chemical composition analysis |
| Rolling | Hot rolling or cold rolling according to thickness | Thickness, flatness and surface control |
| Annealing | Heat treatment to improve structure and stability | Temperature and holding time control |
| Inspection | Final inspection before shipment | Dimension, surface, PMI, certificate review |
Product Inspection
1. Chemical Composition Inspection
Chemical composition analysis is performed to verify nickel content and impurity control. For Invar 36 plate, stable nickel content is important for low expansion performance and material consistency.
2. Mechanical Properties Testing
Tensile strength, yield strength, elongation and hardness can be tested according to customer requirements. Mechanical testing helps confirm material reliability for precision industrial applications.
3. Dimensional Inspection
Thickness, width, length, flatness and tolerance are inspected before shipment to ensure that the Invar 36 plate meets the purchase order or drawing requirements.
4. PMI Testing and Traceability
PMI testing can be used to verify material grade and prevent material mix-up. Heat number traceability and EN 10204 3.1 material certificate can be supplied with the shipment.
Product Packaging
SASA ALLOY provides export-grade packaging for Invar 36 alloy plates to protect the material during sea, air and land transportation.
- Protective Film: Applied to polished or machined surfaces to reduce scratches.
- Waterproof Wrapping: Used to protect plates from moisture during transport.
- Wooden Case Packaging: Suitable for cut plates and precision machined plates.
- Pallet Packing: Suitable for heavy plates and batch shipments.
- Clear Marking: Grade, heat number, size, quantity and customer PO number can be marked on labels.


Applications
Invar 36 alloy plate is widely used where dimensional stability and low thermal expansion are critical. It is especially suitable for high-precision industrial and engineering applications.
| Industry | Typical Applications | Why Invar 36 Is Used |
|---|---|---|
| Precision Instruments | Measuring tools, calibration devices, reference components | Low expansion and high dimensional stability |
| Optical Equipment | Optical frames, laser equipment parts, lens supports | Maintains shape under temperature changes |
| Aerospace | Fixtures, tooling plates, structural reference parts | Stable performance in precision assembly |
| Mold and Tooling | Composite molds, precision tooling, forming tools | Reduces thermal deformation during processing |
| Electronics | Precision components, support plates, sealing components | Controlled expansion and reliable dimensional control |
Why Choose SASA ALLOY?
- Professional supplier of Invar 36 / Alloy 36 / UNS K93603 controlled expansion alloy plate
- Customized thickness, width, length and cut-to-size service available
- Support for ASTM, UNS, EN, DIN, JIS, GB and customer specifications
- Material traceability with heat number control
- EN 10204 3.1 material certificate available
- Chemical analysis, mechanical testing, PMI testing and dimensional inspection support
- Export packaging suitable for international transportation
- Suitable for precision instruments, optical devices, aerospace fixtures, molds and tooling applications
FAQ
What is Invar 36 alloy plate?
Invar 36 alloy plate is a nickel-iron controlled expansion alloy plate with very low thermal expansion. It is commonly used in precision instruments, optical devices, aerospace fixtures and molds.
Is Invar 36 the same as Alloy 36?
Yes. Invar 36 is also known as Alloy 36, UNS K93603, FeNi36 and 4J36 in different standards or markets.
Can SASA ALLOY provide custom size Invar 36 plate?
Yes. SASA ALLOY can supply Invar 36 plate in customized thickness, width, length, cut-to-size plate and machined plate according to customer requirements.
What certificate can be supplied with Invar 36 plate?
EN 10204 3.1 material certificate can be supplied. Chemical composition, mechanical properties, heat number and traceability information can be provided according to the order requirements.
What are the main applications of Invar 36 alloy plate?
Invar 36 alloy plate is mainly used for precision instruments, optical equipment, molds, aerospace tooling, measuring devices and components requiring low thermal expansion.
Contact SASA ALLOY
If you are looking for Invar 36 Alloy Plate, Alloy 36 Plate, UNS K93603 Plate or customized controlled expansion alloy materials, please contact SASA ALLOY with your required grade, size, standard, surface condition, quantity and inspection requirements. Our team can provide professional material solutions for precision alloy applications.




