Railways were among the earliest adopters of aluminum — and today, aluminum extrusions are the backbone of modern rolling stock across India's expanding metro systems, Vande Bharat trains and freight wagons. Here is why aluminum keeps winning, and what to look for in a supplier.
Why aluminum for rail bodies
- Mass reduction. Aluminum body shells are roughly 40–50% lighter than equivalent steel, improving acceleration, braking and energy efficiency.
- Corrosion resistance. Excellent performance under humidity, rain and cleaning chemicals — ideal for metro environments.
- Structural integrity. Large, hollow extrusions replace dozens of welded parts with a single profile, improving crash performance and reducing assembly cost.
- Design flexibility. Long extrusions up to the full coach length can be produced continuously, minimising joints and weld seams.
The modern extrusion car
A typical aluminum metro body uses large-format hollow profiles for the roof, side walls, floor and end beams. Instead of sheets over a frame, the body is built from joined panels that are extruded to their final shape — including mounting channels, door frames and window apertures built directly into the profile. This is known as the integral extrusion construction method and it is one of the main reasons aluminum coaches dominate modern metro fleets.
Alloys used in rail
Most rail extrusions use 6xxx alloys — commonly 6005A, 6063 or 6061 — chosen for weldability, corrosion resistance and strength-to-weight ratio. Wheels, axles and other critical parts rely on 5xxx or 6xxx grades depending on the specification.
Certification is non-negotiable
Rail bodies carry strict documentation requirements: material certificates, traceability, mechanical test reports and weld qualification records. A supplier should be able to provide full metallurgical verification for every batch. At Salco, this traceability is part of an ISO 9001:2015-certified quality system, with an in-house testing lab. Explore our railway applications capability in detail.
Sourcing rail profiles in India
As metro and high-speed programs expand across Maharashtra, Delhi, Gujarat and beyond, the demand for locally manufactured, certified profiles is growing rapidly. Working with an aluminum extrusion manufacturer in India such as Salco — with presses up to 1250T for long, large-format sections and in-house die tooling — keeps lead times short and eliminates import dependence.
If your project specification requires certified rail-grade profiles, get in touch with our engineering team and we will confirm alloy, temper, dimensional capability and certification alongside your delivery programme.