Bimetal Washers Supplier & Exporter in India
Bolt an aluminium busbar straight onto a copper terminal and, sooner or later, galvanic corrosion will eat the joint from the inside. It’s one of those problems electrical and process engineers run into again and again. A bimetal washer is the fix of a single washer with copper on one face and aluminium on the other, so each metal only ever touches its own kind. At Kalpataru Piping Solution, we manufacture ours by permanently roll-bonding a copper sheet onto an aluminium base under controlled pressure, the two metals are mechanically fused into one another rather than glued, plated or welded, so the joint holds up under heat, vibration and years of load cycling. Standard washers ship in the industry-typical 80:20 copper-to-aluminium ratio, though we’ll adjust that split to match your drawing.
Bimetal Steel Washer, Bimetal Plain Washers, Aluminum Copper Bi Metal Washers Stockists, Bi-metallic Washer Manufacturers, AI-Cu bi-metal Washers, Bimetal Washer Exporter in India.
If you’re also sourcing the bimetal sheet these washers are cut from, or separate copper shims and beryllium copper round bar for the same electrical assembly, we stock those too. What follows is the full specification, sizes, layer thickness, mechanical and physical properties, applications and pricing guidance laid out the way an engineer would want it, not the way a brochure would.
- Key Features
- Benefits at a Glance
- What is Bimetal Washer?
- Bimetal Washers Technical Specifications
- Bimetal Washer Technical Parameters (Layer Thickness)
- Mechanical & Physical Properties of Bimetal Washers
- Bimetal Washers Applications / Industries Served
- Roll-Bonded Bimetal Washer vs. Electroplated Washer
- Manufacturing Process & Quality Control
- Certifications & Standards
- FAQ’s About Bimetal Washers
Key Features
- Roll-bonded copper-to-aluminium construction — mechanically fused, not plated or glued
- Standard 80:20 copper-aluminium composition ratio, adjustable to customer specification
- Manufactured and tested to AISI, ASTM, DIN and GB standards
- Thickness range from 1 mm to 3 mm; size range M3 to M100
- Available in round and square profiles, in metric and inch sizing
- High tensile and shearing strength, rated for continuous use up to 400°C
- Excellent resistance to corrosion and stress-corrosion cracking (SCC)
- Every batch verified through PMI testing, macro/micro structure checks and peel-strength testing
Benefits at a Glance
- Stops Galvanic Corrosion: Isolates dissimilar metals so neither one degrades the other at the point of contact — the whole reason bimetal washers exist.
- Reliable Electrical Continuity: The copper face keeps contact resistance low, which matters wherever current has to cross a joint without loss.
- Bonded, Not Coated: Roll bonding creates a true metallurgical bond, so the interface won’t flake, peel or separate the way plating can over time.
- Handles Heat and Load: Rated for continuous service up to 400°C and holds its mechanical properties under repeated thermal and mechanical cycling.
- Built to Spec: We’ll match your drawing’s exact ratio, thickness, diameter and hole pattern rather than force you into a fixed catalogue size.
What is Bimetal Washer?
A bimetal washer solves a problem plated or coated washers can’t: real, lasting electrical continuity between two metals that would otherwise corrode against each other. Ours are made by roll-bonding — pressing copper sheet and aluminium sheet together under enough force that the two metals interlock at a molecular level, forming one continuous piece rather than two layers stuck together. The result is a washer that carries current efficiently on the copper face, resists corrosion on the aluminium face, and stays bonded through thermal cycling, vibration and years of mechanical load — something a plated or electroplated washer simply can’t promise.
Explore our related product lines: Bimetal Products / Bimetal Sheet, Copper Shims and Brass Shims.
Bimetal Washers Types
Bimetal Washers Technical Specifications
Parameter | Specification |
|---|---|
Product Type | Bimetal / Bimetallic Washers — Round & Square |
Material Combination | Copper + Aluminium (standard); Aluminium-Steel on request |
Composition Ratio | 80% Aluminium : 20% Copper (standard, by volume); custom ratios available |
Thickness | 1 mm to 3 mm (custom thicknesses on request) |
Size Range | M3 to M100 |
Governing Standards | AISI, ASTM, DIN, GB |
Manufacturing Process | Roll bonding (mechanical cladding); explosion welding available for special applications |
Max. Continuous Service Temperature | Up to 400°C |
Testing | PMI test, macro/micro structure test, toughness test, pitting corrosion test, peel strength test |
Packaging | Individual poly packs, bulk cartons, palletised export crates with moisture protection |
Bimetal Washer Technical Parameters (Layer Thickness)
Bimetal Type | Base Layer Thickness (mm) | Cover Layer Thickness (mm) |
|---|---|---|
Cu-Al Block | Cu 38–40 | Al 10–12 |
Al-Steel Block | Steel 38–40 | Al 10–12 |
Mechanical & Physical Properties of Bimetal Washers
| Property | Value |
|---|---|
| Material Grade | Copper T2 clad on Aluminium 1060 |
| Copper Purity | 99.9% min |
| Aluminium Purity | 99.6% min |
| Al : Cu Ratio (by Volume) | 80% : 20% |
| Al : Cu Ratio (by Weight) | 55% : 45% |
| Density | 3.8 g/cm³ |
| Resistivity | < 0.019 Ω·mm²/m |
| Tensile Strength | ≥ 150 MPa / mm² (more than 120 N/mm²) |
| Elongation | 27–38% |
| Peeling Strength | More than 12 N/mm |
| Hardness | H24 (Half Hard) |
| Shearing Strength | ≥ 95 MPa / mm² |
| Max. Interface Temperature | ≤ 400°C |
| Interface Combination Rate | 100% (fully bonded, no delamination) |
Bimetal Washers Applications / Industries Served
- Circuit Breakers & Fuse Systems: Support thermal and electrical sensitivity where a clean, reliable circuit interruption is critical.
- Electrical & Electronic Connectors: Maintain electrical continuity and low contact resistance across switches, connectors and distribution panels.
- Power Transmission & Isolators: Minimise galvanic corrosion and preserve current-carrying performance in high-voltage isolators and terminals.
- Fire Safety & Thermal-Sensitive Systems: Used as reliable thermal-response elements in fire alarms and heat-triggered mechanisms.
- Transformers & Busbar Joints: Join copper and aluminium conductors without introducing a long-term corrosion risk at the joint.
- Automotive & Transportation Equipment: Handle vibration and thermal cycling in dissimilar-metal fastening points.
- Offshore & Architectural Structures: Corrosion resistance suited to humid, saline or exposed structural environments.
Roll-Bonded Bimetal Washer vs. Electroplated Washer
Basis | Roll-Bonded Bimetal Washer | Electroplated / Coated Washer |
|---|---|---|
Bond type | True metallurgical bond — metals interlock at the interface | Surface coating — a thin plated layer over a single base metal |
Long-term durability | Bond holds under heat, vibration and load cycling | Coating can flake, wear through or peel over time |
Corrosion protection | Each face is solid, unalloyed metal — no coating to breach | Once the coating is compromised, the base metal is exposed |
Electrical performance | Consistent conductivity across the copper face for the life of the part | Can degrade as plating thins or wears |
Best suited for | Long-service, high-load, high-temperature dissimilar-metal joints | Lighter-duty or short-term applications where cost is the priority |
Manufacturing Process & Quality Control
- Material Selection & Verification — Copper (T2 grade) and Aluminium (1060 grade) sheet is sourced and verified for purity before bonding.
- Roll Bonding — Copper and aluminium sheets are pressed together under high pressure in a controlled rolling process, forming a continuous metallurgical bond between the two layers.
- Blanking & Sizing — Bonded sheet is cut, punched or stamped into round or square washers to the required diameter, thickness and bolt-hole size.
- Testing & Inspection — Every batch is checked through PMI testing, macro/micro structure analysis, peel-strength testing and pitting-corrosion testing.
- Packing & Documentation — Washers are packed with moisture protection for domestic dispatch or export, along with mill and test certification.
- Global Dispatch — Orders are shipped to customers across the Middle East, Asia, Africa, Europe and the Americas through our regular logistics network.
Certifications & Standards
- Manufactured and tested to AISI, ASTM, DIN and GB standards
- PMI (Positive Material Identification) testing on request
- Macro and micro structure verification of the bonded interface
- Peel-strength and shearing-strength testing to confirm bond integrity
- Pitting corrosion testing for service-life verification
Other Available Stock of Bimetal Washers
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- Bimetallic Washer Metals Dealer
- Bimetallic Washers Distributor
- Bimetallic Washer Material
- Copper Aluminum Bimetal Washers
- Bi-Metal Washers Exporter
- Aluminum Copper Bimetallic Washer
- Bimetallic Al-Cu Washer Stockholder
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- Bimetallic Plain Washer
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- Bimetal Washers Price List
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FAQ’s About Bimetal Washers
Our standard bimetal washers are made by roll-bonding copper sheet onto an aluminium base, typically in an 80:20 aluminium-to-copper ratio by volume. The two metals are mechanically fused into a single piece rather than plated, glued or alloyed together.
A bimetal washer has a true metallurgical bond between two solid metal layers, so there’s no coating to wear through. An electroplated washer is a single base metal with a thin plated surface layer, which can degrade or flake off over time, eventually exposing the base metal to corrosion.
Standard thickness ranges from 1 mm to 3 mm, and size ranges from M3 up to M100, in both round and square profiles. Custom dimensions and hole patterns are manufactured to your drawing or sample.
Our bimetal washers are rated for continuous service up to approximately 400°C, making them suitable for electrical, power transmission and thermal-sensitive applications where the joint sees sustained heat.
Power generation, circuit protection, transformers, isolators, automotive assembly, offshore structures and any application where copper and aluminium components need to be joined without triggering galvanic corrosion.
Yes, we regularly export bimetal washers to the Middle East, Asia, Africa, Europe, North America and South America, complete with mill certification and export-ready packaging.
Need Bimetal Washers Built to Your Exact Specification?
Send us the composition ratio, thickness, diameter and quantity you're working with, and we'll come back with a straight quote — not a runaround. We ship bimetal washers and custom-cut pieces across India and to 40+ export destinations, with mill certification and delivery timelines we actually stick to.
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