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Our precision-engineered consumables and tooling are purpose-built for safe, efficient and repeatable aluminothermic rail welding on every track type.
Thermite welding — also known as aluminothermic welding or exothermic welding — is a fusion welding process that uses the intense heat generated by an exothermic chemical reaction between aluminium powder and iron oxide (thermite) to produce molten steel. This molten metal fills the gap between two rail ends, creating a continuous, metallurgically bonded joint that is virtually indistinguishable from the parent rail in terms of strength and microstructure.
First patented in the 1890s by Hans Goldschmidt, thermite welding has evolved into the dominant joining method for railway maintenance worldwide. Its unique combination of portability, speed, and joint quality makes it the preferred choice wherever electric arc or flash-butt welding equipment cannot reach — which is most of the world's existing track.
The process involves five core steps that can be executed entirely in the field without external power sources:
Unlike flash-butt or electric arc welding, thermite welding requires no electricity, generator, or heavy machinery. A complete weld kit weighs under 15 kg and can be carried to any location on the network — a decisive advantage for emergency repairs, remote track sections, and developing-market railways.
The global thermite welding market for railways is estimated to be worth over USD 350 million annually, with consistent growth driven by expanding rail networks in Asia, Africa, and Latin America, as well as aging infrastructure renewal programmes in Europe and North America. According to industry analysts, the sector is projected to grow at a CAGR of approximately 5–7% through 2030.
Major national rail operators — including Network Rail (UK), Deutsche Bahn (Germany), Indian Railways, and CRCC (China) — maintain large standing contracts for thermite welding consumables and services. The shift from bolted fishplate joints to continuously welded rail (CWR) on mainlines has dramatically increased demand for high-quality thermite welds, as every kilometre of CWR requires multiple precision joints during both initial installation and lifecycle maintenance.
China alone operates over 160,000 km of railway and is adding thousands of kilometres annually. Domestic manufacturers such as RMTS are playing an increasingly strategic role in supplying certified thermite welding materials that meet TB/T (Chinese Railway Standard), EN (European Norm), and AREMA (American Railway Engineering) specifications simultaneously — enabling them to compete effectively in both domestic and export markets.
On high-speed rail corridors where trains operate at 250–350 km/h, even a sub-millimetre irregularity at a rail joint can cause dangerous dynamic loading. Thermite welds on HSR must achieve tensile strengths exceeding 880 MPa and Brinell hardness values within ±30 HB of the parent rail. Modern aluminothermic welding powders are formulated with micro-alloying additions (vanadium, chromium, manganese) to match the metallurgy of premium head-hardened rail grades such as R350HT and R400HT.
Maintenance windows on HSR are typically only 3–4 hours overnight. The ability to complete a thermite weld — from mould assembly to final grinding — in under 45 minutes makes it the only practical in-situ repair method within these tight possession windows.
Metro systems present unique challenges: confined underground environments with limited ventilation, tight track geometry on curves and switches, and strict noise and vibration requirements. Thermite welding is particularly well-suited here because it generates no arc flash, requires minimal equipment footprint, and produces joints with excellent fatigue resistance that withstand the high-frequency, low-radius loading typical of urban transit.
Modern one-shot crucible systems — where the thermite charge and crucible are pre-assembled in a factory-controlled environment — have dramatically simplified metro maintenance welding by eliminating on-site powder handling and reducing the risk of moisture contamination.
Heavy-duty crane rails in steel mills, shipyards, and container terminals are subjected to enormous vertical and lateral loads. Welded crane rail joints eliminate the impact loading at bolted joints that accelerates crane wheel wear and damages crane structures. Thermite welding with specialised crane rail moulds (designed for A45, A55, A75, A100, and A120 profiles) is the industry standard for new installation and joint repair in these environments, where electric welding equipment is often impractical due to space constraints or explosion risk.
Seaport rail systems operate in highly corrosive salt-air environments with continuous heavy-load cycles from container handling equipment. RMTS's aluminothermic welding technology provides seamless, corrosion-resistant joints that maintain geometric stability under these extreme conditions, ensuring smooth cargo-handling operations and minimising unplanned downtime.
When a rail is damaged by derailment, vandalism, extreme weather, or fatigue cracking, rapid restoration of track geometry is critical. Thermite welding enables maintenance crews to replace a damaged rail section and produce code-compliant joints within a single possession window — a capability no other welding process can match in a field environment. Emergency repair kits with pre-portioned thermite charges and quick-set moulds are now standard equipment in the maintenance depots of most major rail operators.
The thermite welding industry is undergoing significant technological evolution driven by digitisation, sustainability mandates, and increasingly demanding rail specifications:
Smart ignition systems with embedded temperature sensors and Bluetooth data logging are enabling real-time weld quality monitoring. Data from each weld — reaction time, peak temperature, cooling curve — is uploaded to cloud platforms for traceability and predictive maintenance analytics.
Environmental regulations are driving the development of thermite powder formulations that reduce fume generation and eliminate hazardous additives. Water-based luting compounds are replacing solvent-based alternatives, and recyclable mould materials are being introduced to reduce landfill waste.
Next-generation thermite charges are being engineered to weld ultra-high-strength bainitic rail steels (>1,200 MPa) and premium pearlitic grades used on heavy-haul corridors carrying 30+ tonne axle loads, expanding the addressable market significantly.
Pre-portioned, moisture-sealed one-shot weld kits — where thermite charge, crucible, and mould components are assembled under controlled factory conditions — are becoming the industry standard, reducing on-site preparation time by up to 40% and virtually eliminating human error in charge preparation.
Harmonisation of weld qualification standards (EN 14730, AREMA, TB/T) is enabling certified suppliers to serve multiple markets with a single product range, lowering barriers to entry for export-focused manufacturers and raising the overall quality floor of the global supply chain.
Research programmes in Europe and Japan are developing semi-automated thermite welding rigs mounted on maintenance vehicles, capable of performing mould clamping, pre-heating, and post-weld grinding with minimal manual intervention — addressing labour shortages and improving consistency on high-volume maintenance contracts.
Producing a code-compliant thermite weld is not simply a matter of igniting a chemical reaction. Every component in the weld kit — thermite powder chemistry, sand mould dimensional accuracy, crucible refractory quality, luting sand consistency, and ignitor reliability — must perform within tight tolerances to achieve a joint that will safely carry millions of tonne-kilometres of traffic over its service life.
RMTS operates a 5,500+ m² manufacturing facility in Tianjin, China, with dedicated production lines for each product category. Our quality management system encompasses incoming raw material verification, in-process statistical process control, and finished product testing against EN 14730 and TB/T 1632 standards. Every batch of thermite powder undergoes chemical composition analysis and trial-weld testing before release.
RMTS is a manufacturer specializing in railroad thermit welding materials, based in Tianjin, China. With a factory spanning 5,500+㎡ and 30+ professionals dedicated, we are committed to delivering reliable and efficient thermit welding solutions to clients across the globe. Our products are designed to meet the highest industry standards, ensuring durability and performance in various applications.
We understand that successful welding projects require not only high quality products but also expertise and knowledge. That's why we offer comprehensive on-site training programs to help our clients master the thermit welding process, enabling them to achieve optimal results and build a strong reputation in their respective fields. Additionally, our experienced team provides project welding instruction services, offering hands-on guidance and support to ensure seamless execution, no matter where the project is located.
Driven by a customer-centric approach, RMTS is dedicated to fostering long-term partnerships by delivering exceptional products and services tailored to the unique needs of our clients. Whether you are looking for reliable thermit welding materials, expert training, or project support, RMTS is your trusted partner in achieving welding excellence.
Four pillars that set RMTS apart as a global thermite welding solutions provider.
RMTS have a highly skilled R&D team that works tirelessly to ensure that we produce thermit welding materials that meet the specific needs of each type of rail.
In addition to its strong R&D capabilities, RMTS actively participates in railway projects across China and abroad. The company collaborates with railway authorities, construction companies, and maintenance organizations to provide its expertise and materials for various projects.
By participating in railway projects, RMTS contributes to the development and maintenance of China's extensive railway network. Whether in high-speed rail, urban transit systems, or conventional rail lines, RMTS offers its thermit welding materials and services to ensure the integrity and safety of the rail infrastructure.
Furthermore, RMTS maintains partnerships with research institutions, universities, and industry experts in China. These collaborations enable RMTS to continuously strengthen its R&D capabilities in thermit welding technologies.
RMTS's strong R&D abilities, coupled with its involvement in railway projects, demonstrate the company's commitment to providing advanced thermit welding solutions that meet the specific demands of the railway industry.
Ensures seamless rail joints, providing durable connections, which are critical for maintaining the safety of railway networks.
It's widely used in the welding of crane rails due to its efficiency, reliability, and ability to create strong, durable joints.
Ideal for the confined spaces and tight schedules of metro rail construction and maintenance.
RMTS's aluminothermic welding technology ensures smooth operations for cargo handling in demanding port environments.
Real-world deployments demonstrating RMTS's capability to deliver precision aluminothermic welding solutions on every continent.
As part of the Phase 2 expansion of Jakarta's Mass Rapid Transit (MRT) system, RMTS was contracted to provide aluminothermic welding solutions for the new underground and elevated tracks. The project involved welding 600 rail joints across a 12-kilometer stretch, connecting key areas of the city to reduce traffic congestion.
Our team worked closely with PT MRT Jakarta to ensure the welds met international safety standards. The project was completed on time, and the new line has been operating smoothly since its launch. Jakarta MRT officials highlighted the durability of the welds, which have withstood the high frequency of train movements and tropical weather conditions.
Challenge: The client faced the challenge of welding materials of T62 and P65 rails. The welding process needed to meet the rigorous standards set by the railway authorities, ensuring optimal track performance, longevity, and safety.
Solution: Our team collaborated closely with the client, thoroughly understanding their specific requirements. We provided them with our high-quality thermit welding materials, including welding kits, tailored to suit the T62 and P65 steel rail specifications.
Customer Satisfaction: The client expressed utmost satisfaction with our thermit welding materials. They acknowledged the superior quality, reliability, and technical support provided by our team. Our materials played a crucial role in enabling them to deliver high-quality rail construction projects and meet the demands of the railway industry.
KTMB Railways aimed to improve connectivity across the city's suburbs. RMTS was selected as the most trusted supplier, providing 1,000 aluminothermic welding materials for the new tracks, which included both underground and elevated sections. The project required precise welding to ensure smooth and safe operations, which serves millions of passengers annually.
RMTS's welding materials were chosen for their ability to create strong, seamless joints that could withstand the humid climate and heavy usage. The project was completed ahead of schedule, and the new line has significantly reduced travel times for commuters.
From ignitors and powders to moulds and sealing compounds — every component engineered for precision, safety and repeatability.
