About Us

In House Expertise

Established over 80 years ago Johnson & Allen Ltd is an expanding company in the magnetic particle and dye penetrant inspection industry. With a wealth of experience Johnson & Allen are a market leader in both the design and manufacture of standard and bespoke NDT solutions. All our bespoke systems are designed and built in-house within the 'Steel City' of Sheffield, UK.


World Class Engineering

Johnson & Allen continue to export globally and supply a wide range of industries including aerospace, automotive, rail, oil and gas, military and general engineering. We are a well-established company with a proven track record - Previous satisfied customers including companies such Forgemasters, TATA Steel, Rolls Royce, Vector Aerospace, Gulf Air and BAE Systems.

Johnson & Allen is a BSI ISO 9001: 2015 and Safecontactor certified company and are associate members of the British Institute of Non-Destructive Testing (BINDT) and the Nuclear Advanced Manufacturing Research Centre (NAMRC).


A Professional Company With A Family Feel

Founded in 1938 by Lawrence Johnson, Johnson & Allen is a professional company but still retains its family feel - A uniqueness which will continue with his granddaughter and Managing Director Melanie Robinson and his great grandson Simon Johnson. Supported by an exceptional team, many whom have been in the company for over 20 years Johnson & Allen continually strive to improve and innovate.