Apex EV was ecstatic. The deep drawn housing passed the UN’s ECE R100 crash test with 15% more impact resistance than the welded version, while being 22% lighter. Within six months, Bromford Precision wasn't just making battery housings. They were drawing fuel tank bodies for hydrogen lorries, medical canisters for surgical implants, and electromagnetic shielding enclosures for defence radar systems.
On the 43rd night, at 2:17 AM, the press cycled. The blank was fed, the punch descended, and the metal flowed. The press opened. A single, flawless battery housing emerged—mirror-smooth inside, uniform wall thickness of 1.8mm, with integrated mounting bosses formed in the same stroke. No welds. No leaks. Just strength. deep drawn stamping uk
Eleanor called in a consultant from the University of Sheffield’s Advanced Manufacturing Research Centre (AMRC). The diagnosis was brutal: “You’re treating it like a press shop. You need to think like a metallurgist.” Apex EV was ecstatic
The first week was a disaster. The blanks tore at the corners, leaving jagged scars. The second week, they solved the tearing but introduced earing —wavy ripples at the top edge caused by the metal’s grain structure fighting back. They were drawing fuel tank bodies for hydrogen
The problem was a client in Coventry: Apex EV , a startup building the next generation of electric vehicle battery housings. These weren’t simple trays. They were complex, monolithic enclosures requiring near-micron precision—deep, seamless cavities that could protect volatile lithium cells from crash impacts and thermal runaway. Apex had tried fabricating the housings by welding multiple stamped pieces together, but the welds were weak points. They needed a single piece of metal, transformed into a shape deeper than its own diameter.
They rebuilt the process from scratch. They introduced a multi-stage drawing cycle: first a shallow pre-draw, then an intermediate redraw, then a final ironing stage to thin and smooth the walls. They replaced standard mineral oil with a high-viscosity chlorinated extreme-pressure lubricant. They even adjusted the blank holder force dynamically using sensors—too little, and the metal wrinkled; too much, and it ruptured.
That process is called .