Burkard Scientific Ltd
- Manufacture systems for automatic chemical analysis and instruments for agricultural research and environmental sciences. Includes product specifications.
- http://www.burkardscientific.co.uk/

Trout Tool Company Limited
- Manufactures presstools, presswork, wire eroded parts, jig and fixtures, machined components, and assemblies for the aerospace and automotive industries.
- http://www.trouttool.co.uk/

Metro Engineering and Plating Works Ltd
- Offers anodising and alocrom finishing services to industry including the aerospace, motorsport, marine and medical sectors. Based in Uxbridge.
- http://www.metroplating.co.uk/

L Hodge Engineers (UK) Limited
- Precision engineers providing production and prototype machining, special purpose machine fabrication, CNC milling and turning and toolmaking services.
- http://www.lhodge-engineers.co.uk/

John Guest International Ltd.
- Manufacturer of fittings and pipes for plumbing, central heating systems, drinks dispensers and the motor industry, with headquarters in West Drayton.
- http://www.speedfit.co.uk/

Berkley Engineering
- Precision Engineers in Middlesex, serving the South East of England, specialising in tooling, prototype work, motorsport components, and pressed parts.
- http://www.berkleyeng.com