Quality in the railway industry: what it demands from a supplier of turned components

A rail vehicle runs for thirty years and has to be repairable for all of them. That single fact changes what a supplier of turned components has to promise, and it is not mainly about tolerances.

We supply turned components for several industries, and rail vehicles are one of them. It is also the industry whose demands surprise people most, because the hard part is not the machining.

Thirty years is the design assumption

A car is designed for perhaps fifteen years and built in millions. A tram or a locomotive is designed for thirty or more and built in dozens or hundreds. Everything follows from that difference:

• Spare parts obligation. A component approved today may have to be reproduced, identically, twenty years from now. That means the process, the material specification and the records have to survive as long as the vehicle.
• Traceability over decades. Not just which bar the part came from, but which revision of which drawing, approved by whom and when.
• Change control is strict. In automotive a process change needs re-approval. In rail it can mean a re-qualification of the assembly. A supplier who improves something quietly creates a problem, not a saving.
• Small series, long life. The quantities are far below automotive, but the documentation burden per part is comparable. That combination is what most shops are not set up for.

What the parts have to survive

Vibration and fatigue over a service life measured in millions of kilometres. Corrosion — a vehicle stands outdoors, is washed with detergent and meets track brake dust and de-icing salt. Wide temperature swings. And maintenance: a fastener or a bushing has to come apart again after fifteen years, which puts the emphasis on thread quality and on the right surface protection rather than on a tighter tolerance.

Where we fit

We machine turned components that go into rail vehicle assemblies — pins, bushings, connectors, fasteners, sensor and housing parts — from Ø 2 to Ø 52 mm. We do not make large components such as brake discs; those are far outside what our machines can hold.

Our system is certified to IATF 16949, DIN EN ISO 9001:2015 and ISO 14001:2015. The rail sector has its own scheme, IRIS / ISO 22163, which we do not hold; for turned components most customers work with our automotive documentation, which asks for the same evidence in a different format. If your specification requires ISO 22163 at component level, tell us early and we will say plainly whether we are the right supplier.

More on our quality system, or send a drawing to info@kovinski-izdelki.si.