Tek4 has turned a difficult engineering problem into a profitable business, offering a reminder that Britain can still produce successful engineering companies.
The British firm is joining London's junior market, AIM. That is welcome news at a time when the London stock market has spent much of the past decade contracting. British companies have gone private, while others have been drawn to New York listings. New entrants have not kept pace, leaving investors with fewer growing domestic businesses to choose from.
Tek4, a small engineering firm in Leicestershire, builds highly specialised equipment for some of the world's largest jet-engine and power-generation turbine manufacturers. Its shares start trading on 26 October. The question is whether they are worth buying.
Tek4 tackles demanding engineering problems
Jet engines run at extraordinary temperatures. Inside the turbine, the gas can exceed the melting point of the metal blades, yet those blades still have to endure thousands of hours in service. Engineers solve this with a cooling system built into each blade: relatively cool air travels through hollow internal passages, then escapes through thousands of tiny openings. Spread across the surface, it creates a thin protective film between the metal and the searing gas. That allows the engine to run hotter, improving efficiency while using less fuel. Cutting those openings is no easy job. Turbine blades consist of exceptionally tough alloys covered with ceramic coatings, and each hole has to follow an exact angle - sometimes through a wall less than a millimetre thick. Go too deep, and the drill may strike the opposite wall inside the hollow blade, destroying an expensive component.
Jason Duffin founded Tek4 in 2002 after years spent designing machinery for the turbine industry. Before that, he had helped establish MJ Technologies, a specialist engineering company. His experience led him to focus on the manufacturing problems turbine makers struggled with, instead of entering the crowded general-purpose machine-tool market.
That focus has taken Tek4 well beyond the UK. The Leicestershire-based company supplies aerospace and power-generation firms including Rolls-Royce, GE Vernova and Siemens Energy, with America and Europe accounting for much of its overseas sales.
Customers have solid reasons to remain with the same supplier. Critical engine components must be manufactured to exacting standards, and replacing an approved source means costly retesting that can interrupt production.
Tek4 also provides maintenance, upgrades and specialist tooling, giving the company steadier long-term revenue than investors might expect from a small machinery manufacturer.
Tek4 still has room to grow
Tek4 brought in about 16 million in revenue in 2025 - nearly twice its total from the year before - while reported profit climbed to roughly 4.2 million, more than three times the previous figure. During the year, it sold over 40 machines, with each system generally priced between 300,000 and 750,000. Results will naturally vary from one year to the next at those prices. A few extra sales can sharply lift revenue and profit when factory costs remain largely fixed; a delay affecting only several orders can hurt earnings just as quickly.
Most revenue comes from new equipment, though servicing, maintenance, and upgrades bring in a meaningful share as well. Customers need support for their machines throughout their working lives, which gives Tek4 steadier income and keeps the company closely connected to them. When their needs change, those relationships can also lead to further equipment sales.
Rising aircraft production and investment in electricity generation are driving demand. As modern engines grow more advanced, their cooling systems must handle greater demands. Manufacturers also want to raise productivity while cutting waste. Tek4 plans to install a second assembly line at its Leicestershire factory, which will substantially increase production capacity.
The company is expanding its capabilities, too. In April, it bought Rugby-based InnoLas, a British specialist in advanced laser technology. That deal may improve its existing equipment and create openings in precision sectors such as medical devices and semiconductors, although turbine manufacturing remains the main source of its prospects for now.
Why investors should buy Tek4
The listing will let existing investors sell some of their shares. Corporate financier and early investor Robin Womersley owns 56% of the business, while Duffin owns 34.5%. Duffin is expected to keep a sizeable holding after the listing, leaving his interests closely tied to those of the other shareholders.
Once it begins trading on Aim, Tek4's valuation will need to be weighed against its earnings, growth prospects and any money raised for the business. Risks remain. The company serves a narrow market and relies on relatively few major customers, while the high cost of its equipment means buyers can delay orders. Recent results have been impressive, but sales and profits may not continue growing at the same rate.
Still, Tek4 has turned a hard engineering challenge into a profitable international business, backed by specialist knowledge that rivals would struggle to replicate.
One flotation cannot undo years of decline in London's equity market. Even so, Tek4 shows that Britain can still produce engineering companies with the strength to compete abroad. Its arrival could suit the Aim market well. Investors' returns will depend on the price attached to the shares.
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