Comment: Casting a ‘Giga’ opportunity

The race for electrification has changed the landscape of the automotive sector forever. Gone are the days of three or four companies dominating the global marketplace and dictating the way things are done.

New entrants are encouraging innovation and challenging the status quo, which is music to the ears of businesses like Grainger & Worrall, the world’s leading sand-casting specialist.

We strive to be an ‘enabler’, using our knowledge of materials, castings and 3D printing to deliver solutions to age-old problems that customers previously would have been too risk-averse to try.

Our work in ‘Gigacastings’ is a prime example. Three years in the making, this new ‘prototyping’ process has been driven by an emerging desire from car makers to reduce the number of components that are welded, screwed and glued together to make major body structures.

Traditionally, there would be up 200 different parts assembled in various ways and this is not only costly, time consuming, but also means the vehicle is heavier – not great for firms striving to meet Net Zero targets mandated by global governments.

The conversation moved quickly towards whether an under body could be made using one, or possibly two main parts.

Our engineering and R&D teams relish a challenge, picking up the baton and immediately exploring a range of technical options. The easiest way, offered by most competitors, is the monolithic one-piece sand mould, but too many problems stem from this method if speed, change or optimisation is required.

It quickly became clear that there was a better way, an innovation that addressed the issues of speed to develop, ease of modification and accuracy of parts. 

‘The Vault’

Through a couple of iterations, we eventually arrived at a brand-new process that focused on building lots of different segments that come together in one final casting.

On the shopfloor we call it ‘The Vault’ – an encased system full of magic that is easily scalable. We start with the first one, but we can ramp up to doing many every day and, when customer designs change, modifications are quick and simple to make. This is the key to being an enabler of new technology, the agility to move forward quickly.

Investment in state-of-the-art equipment had always been a priority for Grainger & Worrall and this meant we restyled our vast prototyping factory to accommodate a variety of ‘Gigacasting’ projects at the same time.

Additive manufacturing also played a big role. It gave us the control to build very complex shapes quickly that interlocked, and this was a real gamechanger and fully utilised what is the largest 3D sand printing workshop in the UK. To give you an idea of capability, we can 3D print three tonnes of sand every day.

At this stage we started to get excited. We knew we had a prototyping process that created structures that were right first time and offered the quality of casting that customers could use ahead of heavy investment in high volume diecasting for electric vehicles.

Delivering Results

Fast forward to May 2025. I’m proud to say that our ‘Gigacastings’ process is now a King’s Award winner for Innovation, which is a phenomenal achievement for the business.  It’s not a flash in the pan either, this is the fourth time Grainger & Worrall has been awarded the Queen’s/King’s award.

More importantly though, it has been adopted by many manufacturers in the electrification space and our castings have played a crucial role in the development of under body structures for cars that are now out there on our roads.

NDAs prevent me from naming names, but technology born in Bridgnorth is well and truly shaping the global electrification race.

Time to market has been improved considerably and - on average - more than 35% of weight has been taken out the body of the vehicle. The environmental savings for the car maker and the user are unprecedented.

We are not only making parts, we are also calibrating the process, delivering previously unseen data on how the casting will perform in-situ. Cash used to be king, now there is an argument that data has taken over its place at the top table.

Going forward

Automotive has been driving the ‘Gigacastings’ conversation and that’s where our main focus has been, creating revenues and safeguarding employment for our 500+workforce in Bridgnorth.

This is just the start. What we have done with our prototyping process has altered the direction of conversations in boardrooms across the country.

Management teams now know it is possible to produce full under body structures using just one part, removing the need for hundreds of expensive components. They also know they can do this cost effectively and quickly and, importantly, that aluminium has moved to the material of choice for lightweighting.

Thanks to investment in creating a dedicated ‘Gigacastings’ line in Bridgnorth, we can support our customers to scale up, with the capacity to produce more than 30 prototype ‘pairs’ every week.

It doesn’t need to stop at one vitally important structure for automotive. Grainger & Worrall has already taken orders to make parts for batteries and casings and we are now using ‘Gigacastings’ to push the boundaries of technology in off-highway vehicles, aerospace, defence and applications in marine.

In short, it’s big casting with an equally big future.

Keith Denholm, Chief Technical Officer, Grainger & Worrall