Durability
Designed for long-term service in demanding environmental conditions.
Understanding the method
A Controlled Reaction. A Permanent Bond.
Exothermic welding—also known as thermite welding—joins metallic conductors through a heat-releasing chemical reaction inside a purpose-designed graphite mould. The reaction produces molten metal that flows around the prepared conductors and solidifies into a molecular bond.
Because the finished joint does not depend on mechanical clamping pressure, a correctly executed weld provides dependable electrical continuity, mechanical strength and corrosion resistance for critical earthing and bonding systems.
>1,300°CReaction temperature
3–4 secTypical reaction window
13 stepsDetailed field workflow
Before the weld begins
Prepare the Complete Field Kit.
Use the mould, charge and accessories specified for the conductor sizes and joint geometry. Missing or substituted components can affect safety and weld quality.
Graphite mould
Handle clamp
Weld powder
Starting powder
Metal disk
Flint igniter
Propane torch
Sealing compound
Also required: natural-bristle mould brush, conductor wire brush and the protective equipment specified for the work.
Exothermic welding process
The Complete 13-Step Field Workflow.
The sequence below follows the supplied field procedure directly. Each step is concise, ordered and paired with the original process imagery where available.
-
01Wear Protective Equipment
Wear safety glasses and gloves before handling welding products.
-
02Gather the Correct Equipment
Prepare the mould, clamp, weld material, brushes, igniter and torch. Confirm that the mould is intact.
-
03Fit the Handle Clamp
Slide the clamp into the mould holes with the thumbscrews correctly oriented.
-
04Secure the Mould
Tighten the clamp thumbscrews firmly onto the mould.
-
05Adjust the Closure
Close the grips and adjust the clamp until both mould halves fit tightly.
-
06Clean, Dry and Preheat
Clean and dry the conductor, then preheat the mould to remove moisture. Reheat only when needed between welds.
-
07Position and Seal Conductors
Position the conductors, close the clamp and seal any gap that could cause leakage.
-
08Place the Metal Disk
Block the tap hole with the specified metallic disk.
-
09Add the Welding Mixture
Empty the complete welding-mixture package into the mould crucible.
-
10Apply the Starting Powder
Scatter half over the charge. Close the lid and place the remainder near the ignition opening.
-
11Ignite the Charge
Ignite the starting powder at the top or side using the flint igniter.
-
12Stand Clear During Reaction
Stand clear while the reaction completes in approximately 3–4 seconds.
-
Final step13
Open, Clean and Reuse
After at least two minutes, release the handle grip and open the mould. Remove the joint, clear the slag and clean the mould cavities. The warm mould is then ready for the next weld.
Site planning note
For continuous operation, keep at least two correctly specified moulds available. One mould can cool and be cleaned while the other is prepared, helping the team maintain a safe, unhurried sequence.
Connection characteristics
What a Correctly Made
Exothermic Weld Delivers.
Process control matters because it directly influences the electrical, mechanical and environmental performance of the finished connection.
High Conductivity
Provides a continuous electrical path with minimal connection resistance.
Corrosion Resistance
Avoids a pressure-only interface and reduces problems associated with dissimilar-metal connectors.
Mechanical Strength
Creates a molecular bond capable of withstanding substantial stress and strain.
Stable Performance
Maintains consistent electrical and mechanical properties over time.
Material Versatility
Supports specified joints involving copper cable, tape, brass, stainless steel and copper-coated steel rods.
Permanent Connection
Produces a robust joint that does not depend on bolts or routine retightening.
Controlled Field Process
Uses purpose-matched moulds, charges and safety procedures for repeatable execution.
Where the process is used
Reliable Connections for Critical Infrastructure.
Exothermic welding is selected where long service life, stable conductivity and resistance to loosening are more important than a removable mechanical joint.
Electrical Grounding
Permanent low-resistance joints for earthing grids and electrical grounding networks.
Railway Systems
Durable bonds and selected rail-related connections for signalling and electrical continuity.
Telecommunications
Grounding and bonding connections for communication infrastructure.
Lightning Protection
Reliable current paths for lightning-protection and surge-management systems.
Cathodic Protection
Connections used in systems that protect buried pipelines and structures from corrosion.
Automotive & Aerospace
Specified electrical connections for vehicle and aircraft manufacturing applications.
General & safety instructions
Control the Work Area Before the Reaction.
Exothermic welding is efficient when trained personnel use the correct equipment and respect the thermal, chemical and fire risks of the process.
Personal Protective Equipment
Wear gloves, safety goggles, protective clothing and a face shield where sparks or molten-metal splash may occur.
Prepare the Work Area
Keep the area clean, well ventilated and free from flammable materials before opening any weld-metal package.
Handle Materials Correctly
Keep weld powder and starting powder dry, sealed and protected from heat, moisture and direct sunlight.
Control Ignition
Use only approved ignition equipment, close the mould correctly and stand clear during the reaction.
Cool, Inspect & Test
Allow the weld to cool completely, remove slag, inspect the joint and perform conductivity or specified verification tests.
Why use exothermic welding
Five Practical Benefits of a Permanent Connection.
When the mould, material and field procedure are correctly matched, the resulting joint supports dependable electrical performance with minimal ongoing intervention.
Explore the weld system- 01
Permanent Bond
The connection is not dependent on clamping pressure and is designed to remain stable as it ages.
- 02
Efficient Current Path
High conductivity helps minimise connection losses in grounding and bonding systems.
- 03
Low Maintenance
No routine retightening is required after a correctly completed weld.
- 04
Broad Compatibility
Approved systems can join copper, steel, aluminium and other specified combinations.
- 05
Dependable in Service
The joint is designed to tolerate demanding electrical and environmental conditions without progressive loosening.
Maintenance & storage
Protect the Mould. Preserve Every Cavity.
Correct cleaning and dry storage help the graphite mould remain dimensionally sound and ready for safe reuse.
Typical Mould Life
A graphite mould is commonly suitable for approximately 50–60 field connections when it is correctly selected, handled and maintained.
Careful Handling
Graphite is fragile. Avoid impact, overtightening and rough tools that can chip the mould or damage the weld cavity.
Cleaning Method
Let the mould cool sufficiently, then use the specified brush or tool. Do not scrape or clean a hot cavity aggressively.
End-of-Task Care
Clean the mould inside and outside with a soft cloth, clean all accessories and wrap the mould securely in protective bubble packaging.
Dry Storage
Store moulds, welding powder and cleaned accessories in a cool, dry location away from direct sunlight and moisture.
Quality & supply support
Specified Products. Documented Quality Support.
Amiable Impex supplies exothermic weld powder, graphite moulds and field accessories for projects across India. Orders are coordinated for delivery nationwide, with a typical target window of 10–15 days depending on specification, quantity and destination.
Available quality documentation references CPRI testing, CE and RoHS approvals, together with the company’s stated ISO 9001:2008 quality certification.
Quality
DocumentationTesting · approvals · certification
DocumentationTesting · approvals · certification
Process FAQs
Clear Answers for Safer Field Execution.
Quick technical guidance covering temperature, cooling time, mould life, moisture control, inspection and storage.
Ask a technical question01What is the exothermic welding process?
Exothermic welding is a controlled chemical process that produces molten metal inside a graphite mould. The molten metal surrounds the prepared conductors and solidifies into a permanent molecular connection.
02How hot does an exothermic welding reaction become?
The aluminium and copper-oxide reaction generates temperatures above 1,300°C. Exact reaction behaviour depends on the specified weld material, mould and connection design.
03How long should the mould remain closed after ignition?
This guide specifies waiting at least two minutes before opening the mould. Always follow the cooling time stated for the selected system and joint configuration.
04Why must the graphite mould and conductors be dry?
Moisture can expand rapidly when exposed to molten metal and can compromise both safety and weld quality. Preheating helps remove absorbed moisture before the charge is loaded.
05Can an exothermic welding mould be reused?
Yes. A mould may typically produce approximately 50–60 field connections when it remains intact and is cleaned and handled correctly. Actual life depends on use and condition.
06What should be checked after the weld is complete?
Inspect the joint for complete fill, a uniform surface, cracks and other visible imperfections. Remove slag and complete electrical or project-specific testing when required.
07How should exothermic welding powder be stored?
Keep weld powder and starting powder sealed in a cool, dry environment away from moisture, heat and direct sunlight, following the product safety information.
Plan the connection correctly
Match the Mould, Charge and Joint Geometry.
Share the conductor materials, sizes, joint type, project quantity and delivery location. Our team can help identify the appropriate exothermic welding system.