Engineering Company Index - O
- O A Curtis & Sons - Newmarket
- O C Jewellery Manufacturers and Design - Chester
- O E S Medical Ltd. - Abingdon
- O I L Engineering Ltd. - Aberdeen
- O K International Ltd. - Eastleigh
- O L D Engineering Co. Ltd. - Hinckley
- O S F Ltd. - Wolverhampton
- O'Dell Signs - Hayle
- O'Hanlon Engineering - Dungannon
- O'Neill and Co Ltd - Glasgow
- O'Neill Medicalia Ltd. - Liverpool
- O-Vee Spring Gauges Ltd - Watford
- O.S. Engineering - Liverpool
- Oadby Plastics Ltd - Leicester
- Oak Engineering - Rhyl
- Oak Engineering Co. Ltd. - Hebburn
- Oak Leaf Joinery - Peterborough
- Oak Lodge Designs - Alfreton
- Oak Refrigeration and Mechanical Services Ltd - Leicester
- Oak Street Fabrication - Norwich
- Oak Tree Cabinet Makers - Swindon
- Oakdale Contractors Ltd. - Bradford
- Oakdale Project Management Services Ltd - Doncaster
- Oakenhurst Aircraft Services Ltd. - Rayleigh
- Oakes Bros Ltd - Horsham
- Oakes E P & Son - Smethwick
- Oakfield - Bristol
- Oakham Sheet Metal Co. Ltd. - West Bromwich
- Oakhinge Ltd. - Walsall
- Oakland Conservatories - Ashton under Lyne
- Oakleigh Cases Ltd. - Potters Bar
- Oakley Products Ltd. - Corby
- Oakmace Exhibitions Ltd. - Waltham Abbey
- Oakrange Engineering Ltd - Rotherham
- Oakwood Fencing Services Ltd. - Colchester
- Oakwood Fuels Ltd. - Newark
- Oasis Metal Products Ltd. - Monmouth
- Oaston Engineering Ltd. - Nuneaton
- OAT (Oxford Automotive Technologies) Ltd - Daventry
- Oates Fork Lift Trucks - Selby
- Obek (U.K.) Ltd - Wellingborough
- Obelisk Engineering - Wellingborough
- Oberon Engineering Ltd. - Havant
- Obscura Access - Braintree
- OCCO Coolers Telford Ltd - Telford
- Ocean Kinetics Ltd. - Shetland
- Oceaneering International Services Ltd. - Aberdeen
- Octo Product Development Ltd - Gateshead
- Octopus Collation Solutions Ltd. - Derby
- Odin Consulting Engineers Ltd. - Glasgow
- Odin Engineering Ltd. - Coventry
- Odlings M C R Ltd. - Ellesmere Port
- Odran Helay - Corsham
- Odyssey Technologies Ltd. - Farnham
- Oeg Offshore Ltd. - Aberdeen
- OEP - A Division of Walters Group Holdings Ltd - Kidlington
- Oerlikon Balzers - Milton Keynes
- Oetiker U K Ltd. - Horsham
- Off Zero Ltd - Cullompton
- Off-Road Northern Ireland Ltd. - Belfast
- Offaplan Ltd. - Daventry
- Offerframe Ltd - Leicester
- Office Water Coolers Ltd - Rugeley
- Offset Services Ltd. - Warrington
- Offshore Stainless Supplies Ltd - Walsall
- Ogden (Transteel) Ltd. - Pudsey
- Ogden Fibres Ltd. - Keighley
- Ogilby Construction Ltd. - Chesterfield
- Ogp Uk Ltd. - Derby
- OHM Security Ltd - Leeds
- Ohmicron Ltd - Poole
- Oil and Gas Systems Ltd - Ely
- Oil Salvage Ltd - Bootle
- Oil Services South West Ltd. - Okehampton
- Oil States Industries (U K) Ltd. - Aberdeen
- Oil States Klaper Ltd - Aberdeen
- Oilfast Scotland Ltd - Bellshill
- OK Services - Sutton in Ashfield
- Okay Engineering Services Ltd. - Market Harborough
- OKW Enclosures Ltd - Fareham
- OLAER Fawcett Christie Ltd - Deeside
- Old Devon Pine - Honiton
- Old Ford Ltd. - London
- Old Manse Joinery - Coleraine
- Old Park Engineering Services Ltd. - Cradley Heath
- Old Town Engineering Co. Ltd. - Swindon
- Oldbury Engineering Co. Ltd. - Horley
- Oldbury UK Ltd - Wolverhampton
- Oldham Blinds - Oldham
- Oldham Caravans - Manchester
- Oldham Electroplating Co. Ltd. - Oldham
- Oldham Engineering Ltd. - Oldham
- Oldham Optical UK - Scarborough
- OLE UK Ltd - Chichester
- Olenol Ltd. - Congleton
- Oleo International Ltd - Coventry
- Olicana Products Ltd - Ilkley
- Olivari Uk Ltd. - Brentwood
- Olive & Padgett Ltd. - Heckmondwike
- Oliver Douglas Ltd. - Leeds
- Oliver Goldsmith Eyewear Ltd. - Borehamwood
- Oliver's Army Ltd. - Worcester
- Ollyswood Joinery - Pulborough
- Olney Pine and Picture Gallery - Milton Keynes
- Olton Transmissions - Birmingham
- Olympia Testing (Holdings) Ltd. - Brierley Hill
- Olympia Triumph Manufacturing Ltd. - Swanage
- Olympic Conveyor Services Division - Bodmin
- Olympic Welding Ltd. - Norwich
- Olympus Technologies Ltd - Huddersfield
- Olympus Transmissions Ltd. - Wolverhampton
- Omar Homes Ltd. - Brandon
- Omar S Chana - Southall
- Omc Joinery Ltd. - Ilkeston
- Omega Blacksmiths - Glasgow
- Omega Building Services Ltd. - Caterham
- Omega Citylifts Ltd. - Welwyn Garden City
- Omega Controls - Newark
- Omega Diagnostics Ltd. - Alva
- Omega Foundry Machinery Ltd. - Peterborough
- Omega Lift Services Ltd - Edinburgh
- Omega Pistons Ltd. - Halesowen
- Omega Resistance Wire - Potters Bar
- Omega Signs Ltd. - Leeds
- Omega Technical Services (U K) Ltd. - Wrexham
- Omegaslate (UK) Ltd - Kidderminster
- Omicron Cutting Technology Ltd - Bristol
- OML Ltd - Ashton under Lyne
- Omni Design International Ltd. - Solihull
- Omni Instruments - Dundee
- Omni Pine & Cane Furnishing - Edinburgh
- Omnia H V & Rail Ltd. - Uttoxeter
Omnikote Ltd - Aylesbury- Omnitrack - Stroud
- Omron Electronics Ltd - Milton Keynes
- Omron Healthcare U K Ltd. - Milton Keynes
- On Tap Services - Slough
- On the Level Property Services Ltd. - Leighton Buzzard
- On Time Joinery Ltd. - London
- Ondrives Ltd - Chesterfield
- One Off Engineering - Barnsley
- One Step Joinery Ltd - Swindon
- One Stop Mobility Ltd. - Woking
- One Stop Pumps Ltd - Barnsley
- One Stop Sealing Ltd - Hull
- ONE51 Es Metals (North) Ltd. - Bolton
- Oner Signs & Leisure - Cardiff
- Onet Technologies Uk Ltd. - Southampton
- Ongor Plating Service - Ongar
- Online Engineering Systems Ltd - Stonehouse
- Online Furnace Services Ltd - Greenock
- Online Plumbing Services - Abbots Langley
- OnSite Central Ltd - Wantage
- Onsite Services - Southampton
- Onus Technologies Ltd - Sandhurst
- Opas (Southern) Ltd. - Worthing
- Open Date Equipment Ltd. - Mitcham
- Operational (U K) Ltd. - Runcorn
- Opperman Mastergear Ltd. - Newbury
- Opra Packaging Ltd. - Walsall
- Oprima Ltd. - Oxford
- Opt Out Engineering Ltd. - Bristol
- OPT4MOBILITY Ltd - Teddington
- Optek Ltd. - Abingdon
- Optical Communication Services Ltd. - Immingham
- Optical Metrology Centre - Bishops Stortford
- Optico Ltd. - Hitchin
- Optima - London
- Optima Control Solutions Ltd - Blackburn
- Optima Design Associates Ltd - Mansfield
- Optima Stainless - Kings Lynn
- Optimation Ltd - Ilkeston
- Optimeasure Ltd - Wootton
- Optimise Heat and Steam Ltd - Sudbury
- Optimum Conservatory Roofing Ltd - Bolton
- Optimum Engineering Ltd - Hemel Hempstead
- Optimum Group Services Plc - Greenford
- Optimum Mobility Ltd - Malmesbury
- Optimum Precision Engineering Ltd - Ely
- Optos Plc - Dunfermline
- Opus Engineering Services Ltd. - Lowestoft
- Opus Metrology - Corby
- Ora Technologies - Bristol
- Oracle Storage Systems Ltd - Newbury
- Oralgate Ltd. - Sheffield
- Orange Mountain Bikes Ltd. - Halifax
- Oranworth Ltd - Southampton
- Orb Engineering - Motherwell
- Orbit Bearings and Transmission Ltd - Cradley Heath
- Orbital Foods Ltd. - Bury St Edmunds
- Orbital Gas Systems Ltd - Stone
- Orbitec Ltd - Derby
- Orchard Industrial Ltd - Bury St Edmunds
- Orchard Installations - Bristol
- Orchard John & Co - Redruth
- Orchard Materials Ltd. - Bristol
- Orchard Partners - London
- Orchard Two Ltd - Bootle
- Organic Recyling - Peterborough
- Organically Coated Steel - Kidderminster
- Oriental Motor (Uk) Ltd. - Basingstoke
- Original Bathrooms Ltd. - Richmond
- Orion - D Gow and Son - Lybster
- Orion Automation Ltd - Huntingdon
- Orion Display - Basildon
- Orion Electrotech Ltd - Reading
- Orion Engineering Ltd. - Nantwich
- Orion Engineering Services Ltd - Inverness
- Orion Optics - Crewe
- Orion Precision Castings Ltd. - Hayle
- Orion Windows Ltd - York
- ORLIN Technologies Ltd - Bedford
- Ormonde Joinery Products Ltd. - Surbiton
- Ormskirk Windows and Joinery - Ormskirk
- Ornamental Gates - Burton on Trent
- Ornamental Ironwork - Ashton under Lyne
- Ornamental Ironwork - Bridlington
- Ornamental Metals - Kirkcaldy
- Oro Ltd - Leeds
- Orostream Air Conditioning Ltd - Crowborough
- Orpington (Joinery) Ltd. - Orpington
- Orscheln Europe - Rugby
- Orseal Ltd. - Bolton
- Ortak Jewellery Ltd - Orkney
- Ortho-Clinical Diagnostics - Cardiff
- Orthopaedic Innovation Ltd - Sheffield
- Orthos (Engineering) Ltd - Market Harborough
- Orthos Ltd. - Bristol
- Ortlinghaus U K Ltd. - Bromsgrove
- Ortomotion Ltd. - Corby
- Orwell Engineering Co (Liverpool) Ltd - Liverpool
- Osborn Steel Extrusions Ltd - Bradford
- Osborn-Unipol (UK) Ltd - Chepstow
- Osborne Engineering Ltd. - Cramlington
- Osborne Precision Sheet Metal Ltd - Hungerford
- Osborne Refrigerators Ltd. - Bognor Regis
- OSG UK Ltd - Basildon
- Oso Hotwater (U K ) Ltd. - Gateshead
- Osprey Business Systems Ltd. - Southampton
- Osprey Windows Ltd. - Chester
- OSS Group - Liverpool
- Ossett Steel Services Ltd. - Pontefract
- Osteotec Ltd. - Christchurch
- Osterley Heating & Plumbing Supplies Ltd. - Hounslow
- Otc Precision Ltd. - Wolverhampton
- Othello Blinds Ltd - Colchester
- Otis Ltd. - London
- OTM Servo Mechanism Ltd - Egham
- Otmertold Ltd. - Abergele
- Ottaway Engineering Ltd - Eastleigh
- Otter Wrought Iron Products - Halstead
- Otto Simon Ltd - Cheadle (Cheshire)
- Oulton Forge - Lowestoft
- Outlane Engineering Company - Huddersfield
- Outlook Stockholders Ltd. - Coulsdon
- Outokumpu Stainless Distribution - Sheffield
- Outrams (Ironmongers) Ltd. - Doncaster
- Ouzledale Foundry Co. Ltd. - Barnoldswick
- Ovako Ltd. - Dudley
- Ovalway Hydraulic Engineering Ltd. - Middlesbrough
- Ove Arup & Partners - Bristol
- Ove Arup and Partners - Leeds
- Ove Arup and Partners - Solihull
- Ovendens Engineers Ltd. - Folkestone
- Overmarsh Engineering Ltd. - Bicester
- Overprint Packaging Ltd - Harefield
- Owen Holland (Engineering) Ltd. - Blandford Forum
- Owens Corning Automotive (Uk) Ltd. - Lancaster
- Owlthorpe Garden Furniture & Fencing - Sheffield
- Oxford Engineering Ltd. - Abingdon
- Oxford Filtration Ltd. - Windsor
- Oxford Precision Components - Oxford
- Oxford Products Ltd - Witney
- Oxford Sensor Technology Ltd. - Abingdon
- Oxford Sunblinds - Southampton
- Oxford Time Recorders - Witney
- Oxi-Black and Phosphate Ltd - Darlaston
- Oxman & Walker - Bridgwater
- Oxoid Ltd. - Basingstoke
- Oxton and Hoylake Iron Works - Wirral
- Oxton Engineering Co. Ltd. - Birkenhead
- Oxus Gold Plc - London
- Oxylitre Ltd. - Manchester
- Ozark Systems - Oldham
- Ozone Industries Ltd - Farnborough