Invar Plates | Ultra-Low Expansion Alloy Plates for Precision, Cryogenic & Power-Critical Structures
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When a liquefied natural gas (LNG) export terminal discovered that conventional carbon steel support frames were warping just a few millimetres during cooldown, laser-aligned pipe racks and metering skids fell out of tolerance, forcing slowdowns and costly rework. Switching critical frames, gauge bases, and sensor mounts to Invar 36 Plates a nickel‑iron alloy with a coefficient of thermal expansion roughly one‑tenth that of carbon steel up to about 200–260°C cut alignment drift by over 80% and allowed the plant to run repeated thermal cycles without losing calibration, delivering a step change in reliability for its cryogenic and precision systems.
For procurement heads, design engineers, fabricators, OEMs, and hardware or industrial supply stores serving chemical, oil & gas, marine, pharma, and power generation, Invar plates (Alloy 36, UNS K93600 / K93601, W.Nr. 1.3912) solve a very different problem than stainless or high‑temperature nickel alloys: dimensional stability. With about 36% nickel and the balance iron, Invar exhibits a coefficient of thermal expansion (CTE) near 1.2–1.5 × 10⁻⁶ K⁻¹ in the typical service range about one‑tenth that of carbon steel while retaining good strength and toughness from cryogenic temperatures up to roughly 200–260°C.
Aurico Alloys LLP can support these needs as a trusted Nimonic Plates supplier and, in parallel, as an authentic, quality‑focused supplier, manufacturer and stockist of Invar Plates in India with exports abroad, offering cut‑to‑size plate, sheet and shim stock with UNS K93600 / K93601 identification, EN 10204-compliant test certificates, and project documentation for LNG, precision metrology, composite tooling, and cryogenic piping projects. Hardware and industrial supply stores can add Invar plates and shims to inventory to serve instrument makers, maintenance crews, and OEMs that previously had to import small lots at high cost.
In such cases, Nimonic plates can be deployed in the hottest gas paths and furnace internals, while Invar plates handle cold or moderate‑temperature structures where movement must be controlled to microns rather than millimetres, giving engineers two very different but complementary tools to optimise reliability and lifecycle cost.
High-quality Invar Plates ready for industrial use.
Specification Overview
| Supplier & Role | Aurico Alloys LLP – Invar plates supplier, stockist, exporter in India to abroad |
|---|---|
| Principal Alloy | Invar 36 / Alloy 36, low‑expansion Fe–Ni alloy containing about 36% Ni |
| UNS Designations | UNS K93600, UNS K93601 |
| Werkstoff / EN | W.Nr. 1.3912, FeNi36 |
| Typical Standards | One plate, sheet and strip specification, in the identity table below. VDM also lists DIN 17745 and SEW 385 for sheet and plate. Inspection certificates to EN 10204. |
| Thickness Range | 4.75 mm – 150 mm |
| Temperature Range for Low CTE | From cryogenic temperatures up to roughly 200–260°C (≈400–500°F) with extremely low expansion |
| Available Forms | Plates, sheets, strip, shims, tooling plate and bar |
UNS & Equivalent Grades
| Property | Value |
|---|---|
| UNS number | K93600 / K93601 / K93602 / K93603 |
| Werkstoff / EN number | 1.3912 |
| EN designation | Ni36 |
| Density | 8.1 g/cm3 |
| Melting range | 1430 °C |
| Specific heat capacity (20 °C) | 486 J/kg·K |
| Thermal conductivity (20 °C) | 12.8 W/m·K |
| Electrical resistivity (20 °C) | 78 µΩ·cm |
| Modulus of elasticity (20 °C) | 143 GPa |
| Curie temperature | 230 °C |
| Plate, sheet and strip specification | ASTM F1684 / B753 / B603 |
Identifiers and physical constants for Invar 36. A dash means no such designation is published for this grade.
Stock & Product Availability
As an Invar plates stockist, Aurico Alloys LLP can offer plate and sheet thicknesses commonly used for LNG supports, composite tooling, gauges, and metrology bases, typically in the range of a few millimetres up to several tens of millimetres, alongside thin strip and shim for fine adjustments and instrument mounting faces. Cut‑to‑size and tight dimensional tolerances help fabricators and OEMs avoid scrap and machining time on a relatively premium alloy.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Nickel (Ni) | 35 | 37 |
| Chromium (Cr) | — | 0.25 |
| Iron (Fe) | — | Balance |
| Cobalt (Co) | — | 0.5 |
| Manganese (Mn) | — | 0.6 |
| Silicon (Si) | — | 0.4 |
| Carbon (C) | — | 0.05 |
| Sulfur (S) | — | 0.015 |
| Phosphorus (P) | — | 0.015 |
Composition limits for Invar 36. 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 (Room Temperature, Annealed) | Typical Value for Invar 36 Plate/Sheet |
|---|---|
| Ultimate Tensile Strength | ≈430–490 MPa (≈63–71 ksi) |
| Yield Strength (0.2% offset) | ≈240–260 MPa (≈35–38 ksi) |
| Elongation | ≥30–42 % in 50 mm gauge length |
| Hardness | ≈130–150 HB in typical annealed plate |
| Coefficient of Thermal Expansion | ≈1.2–1.5 × 10⁻⁶ K⁻¹ from about −100°C to +200°C (≈one‑tenth carbon steel) |
| Service Temperature Range for Low CTE | Cryogenic to about 200–260°C, above which expansion rises |
| Cryogenic Behaviour | Good strength, ductility and impact toughness down to LNG and liquid‑nitrogen temperatures |
Applications & Benefits
- Chemical & Oil & Gas: Invar plates used in gauge frames, instrument supports, reference standards, and cryogenic pipe supports reduce drift and misalignment when systems cycle between ambient and cryogenic or moderately elevated temperatures, outperforming carbon steel and stainless that expand and contract far more.
- Marine & Power Generation: Invar plate tooling for composite blades, precision fixtures in turbines and generators, and support structures near cryogenic LNG loading arms benefit from Invar’s low expansion, while Nimonic plates can handle nearby hot‑section loads.
- Pharma & Precision OEMs: In metrology frames, optical benches, and precision dosing or inspection equipment, Invar plates and shims reduce recalibration frequency because the structure moves very little with daily temperature variations, which is not achievable with plain steel.
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
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
Invar plates from Aurico Alloys LLP, built around Alloy 36 (UNS K93600 / K93601, W.Nr. 1.3912) and international standards such as ASTM F1684 and ASTM B753, give chemical, oil & gas, marine, pharma, and power users an ultra‑low expansion, cryogenically tough plate solution that conventional carbon and stainless steels simply cannot match—are your most dimension‑critical supports, gauges, and tooling still relying on alloys that move ten times more than Invar every time the temperature changes?