TEK4 Group (AIM:TEK4) shares started trading on AIM on Monday, under the ticker TEK4, alongside the London debut was a £24.75m placing of shares.
The UK-based precision engineering business designs, manufactures and supports specialised hole-drilling systems used to make cooling holes in aero engine and industrial gas turbine components. The stock market float has valued the company at £42m (with 21m shares in issue).
The placing comprised 12.38m shares priced at 200p each, with proceeds split: the bulk (£22.75m is going to selling existing shareholders) and around £2m was raised for the company with the sale of new shares.
The company highlighted that the placing was significantly oversubscribed.
"We are delighted to be listing on AIM today and with the strong level of support from such a large range of high-quality institutional investors," said Duffin.
"As the aerospace and power-generation industries seek to produce engines that operate at higher temperatures, more efficiently and for longer, the importance of the technology sitting behind their cooling systems is constantly increasing," he said.
Founded in 2003 by chief executive Jason Duffin, TEK4 has built a portfolio of electrical discharge machining (EDM), laser machining, laser ablation and STEM drilling technologies, and says it has achieved six years of self-funded growth. Earlier this year, for the 2026 financial year, the company reported revenues of £16.2m with an operating margin of 27.7%, no debt and net assets of £5.2m.
The company is self-funding construction of a 12,000 square foot factory extension, adding 75% to its existing factory space.
In April 2026, TEK4 acquired Innolas, a laser technology specialist, to expand its in-house laser capabilities and support entry into the medical devices and semiconductor markets.
TEK4 said the London listing is intended to provide liquidity for selling shareholders, secure the business's long-term future as an independent operator, support capital access for growth given its blue-chip client base, aid retention of engineering talent through equity incentives, and back expansion into new areas such as medical devices.
More than 200 of the company's machines are currently in active service, with over 40 supplied since April 2025, underpinning recurring aftermarket revenue from servicing, spares, consumables, training and process development.
Following admission, Duffin holds 6.12m shares, equivalent to 29.2% of the enlarged share capital, with chief commercial officer Ben Pratt holding 5.5%.
Institutional shareholders include Premier Fund Managers, TrinityBridge, Gresham House Asset Management, Schroders Investment Management, Harwood Capital, Stancroft Trust, Downing, Janus Henderson Investors UK and Slater Investment.