Engineering jobs in Woking

Displaying 1-50 of 1,278 jobs

Refine search

Your current filters

Remove search filter Woking, Surrey (up to 15 miles) Clear all Clear all filters

The position you are looking for is no longer available, but here are some similar jobs that might interest you

  1. Medical Field Service Engineer, Pathology Laboratory Diagnostics

    Posted 2 hours ago by TRS Consulting

    Remote job
    Location:
    Woking
    Job Type:
    Permanent

    Medical Field Service Engineer (Pathology Laboratory Diagnostics. Basic Salary £44,000. Bonus £5,700. Company Car (electric / hybrid options available. Excellent Benefits Package. * An excellent opportunity for experienced Service Engineers from a range of electronics systems backgrounds to join a … more

    Apply Now
  2. Site Engineer

    Posted yesterday by Deploy UK Rail

    Salary:
    £250 - £300/day
    Location:
    Woking, Surrey
    Job Type:
    Contract, Temporary

    Site Engineer with highways experience required between June and September to join an organisation working on an M25 junction upgrade, which will reduce congestion and improve safety. Role. Provide site teams with permits to dig, including utility drawings. Setting out and site surveys (total … more

    Apply Now
  3. Masking Operative

    Posted yesterday by Pertemps Camberley

    Salary:
    £11/hour
    Location:
    Woking, Surrey
    Job Type:
    Contract, Temporary

    Our client is a specialist coatings solutions provider for engineering components. They are looking for a Masking Operative on a temporary to permanent basis for immediate interview. Apply NOW. Purpose of Job. Primary functions are the masking and/or demasking of customer product being parylene … more

    Apply Now
  4. Trainee Recruitment Consultant - Surrey

    Posted yesterday by Pinnacle Recruitment

    Salary:
    £20,000 - £26,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Pinnacle Recruitment are professional specialist head-hunters, recruiting within niche Technical market sectors. Having been established for 15 years, we take pride in focusing on talented individuals for high profile roles. Proactive recruitment methods are the backbone of our service and indeed … more

    Apply Now
  5. PACS Engineer/Technical Consultant (Flexible location)

    Posted 2 days ago by Capgemini Engineering

    Salary:
    £40,000 - £50,000/annum plus a range of flexible benefits
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    The Role. We are looking for several PACS Engineers/Technical Consultants to support our Life Sciences Team. This is an exciting opportunity which offers plenty of opportunity to grow within the team and also offers an attractive reward package. The position offers flexibility in terms of location, … more

    Apply Now
  6. Penetration Tester

    Posted 5 days ago by TATA Technologies

    Featured job
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Role description. At Tata Technologies we make product development dreams a reality by designing, engineering and validating the products of tomorrow for the world's leading manufacturers. Due to our continued growth we are now recruiting for a Penetration Tester to be based at our clients site in … more

    Apply Now
  7. Cyber Security Engineer

    Posted 5 days ago by TATA Technologies

    Featured job
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Role description. At Tata Technologies we make product development dreams a reality by designing, engineering and validating the products of tomorrow for the world's leading manufacturers. Due to our continued growth we are now recruiting for a Cyber Security Engineer to be based at our clients … more

    Apply Now
  8. Mechanical Engineer

    Posted 5 days ago by Bennett and Game Recruitment LTD

    Salary:
    £34,000 - £40,000/annum Travel Pay, Overtime, Profit Share
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Mechanical Engineer required in the M3/M4 North region for our client, a leading HVAC company that has 6 regional offices and has been expanding since it formed over 20 years ago. They offer their customers a complete turnkey solution for the installation, service, maintenance, fault finding and … more

    Apply Now
  9. Graduate Transport Planner

    Posted 6 days ago by Penguin Recruitment

    Remote job
    Salary:
    £22,000 - £26,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    The Company. The Client is a leading Multi-disciplinary in the UK, who specialise in Transport Planning, Infrastructure Design and Environmental Assessments. They work on a diverse range of development projects and schemes, making representations for Local Plans, inform masterplans and support … more

    Apply Now
  10. Instrumentation Engineer

    Posted 6 days ago by Ernest Gordon Recruitment Limited

    Remote job Quick apply
    Salary:
    £35,000 - £42,000/annum Progression + Training + Company Ben
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Instrumentation Engineer. £35,000- £42,000 + 25 Days Holiday + Remote (Occasional Travel to Site) + Pension + Healthcare + Training + Company Benefits. Woking, Surrey. Are you an Instrumentation Engineer looking for a new and exciting opportunity to work for a market leading company, heavily … more

  11. Commercial Catering Engineer

    Posted a week ago by Essentia Solutions Group

    Salary:
    £40,000 - £45,000/annum Overtime + Door to Door
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Essentia Solutions are currently working with an excellent and expanding commercial catering project and service business based in Surrey. With over 30 years industry experience, the provide both project and servicing to a wide range of clients ranging from Hotels, Restaurants and Schools. They are … more

    Apply Now
  12. Senior Design Engineer

    Posted a week ago by Owen Daniels Consultancy

    Location:
    Surrey
    Job Type:
    Permanent

    Do you have experience working as a Senior Design Engineer. If so, this position could be perfect for you! Our client is a global, leading manufacturer of ground support equipment and access ways. They are looking for an experienced Senior Design Engineer to join their growing team. The client … more

    Apply Now
  13. Lift Engineer

    Posted a week ago by REClifts

    Remote job
    Salary:
    £40,000 - £45,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Lift Engineer. Service, Repair Callout. Lift Service Division. Woking. Basic Salary: £40,000 - £45,000. Benefits. Van. Fuel card. 25 Days Holiday. Pension. Opportunity to work for one of the biggest global Engineering companies. Clear progression route to Technician, Tester or Senior Management if … more

    Apply Now
  14. Electrician

    Posted a week ago by Calibre Search

    Remote job
    Salary:
    £38,500 - £40,000/annum van, paid travel, overtime, callout
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    An excellent opportunity has arisen for an experienced Electrician to join one of the country's leading Facilities Management companies working in Woking and surrounding areas. The ideal candidate will have a strong electrical background and hold electrical qualifications such as NVQ/SVQ Level 3 in … more

    Apply Now
  15. Senior Town Planner

    Posted a week ago by Penguin Recruitment

    Remote job
    Salary:
    £35,000 - £45,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    The Company. My client, a leading Real-Estate and Planning Consultancy with more than 170 staff across their 12 offices, is looking for an experience Senior Town Planner to join the continued and ever-expanding planning team in Woking. The successful candidate will have excellent career development … more

    Apply Now
  16. Purchaser

    Posted a week ago by Omni Group Ltd

    Salary:
    £30,000 - £35,000/annum dependent on experience
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    PURCHASER - WOKING. Who we are looking for. People with previous experience in a purchasing role, preferably for a manufacturing company. Necessary experience. Using MRP systems. Understanding of stock levels & demands. Understanding of re order levels. About the role. Type: Permanent. Location: … more

    Apply Now
  17. Ex-Forces Engineer

    Posted a week ago by Rise Technical Recruitment

    Salary:
    £37,000 - £40,000/annum Overtime Opportunities, Perks
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Ex-Forces Engineer. Woking. £37,000 - £40,000 + Pension + Holidays + Benefits Package + Overtime Bonus + Relocation Support + Full Training. Are you an Engineer in the process of leaving the Armed Forces or one that has recently left and want to advance a specialist career within a highly-valued … more

    Apply Now
  18. Field Service Engineer

    Posted a week ago by Future Engineering Recruitment Ltd

    Remote job
    Salary:
    £28,000 - £31,000/annum Training + Stability + Package
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Field Service Engineer. Woking. £28,000 - 31,000 Basic + On Job Training + Stability + Support + Flexibility + Work Life Balance + Package + IMMEDIATE START. Are you looking for a field service engineer for a company that will invest in your future through training with a supportive team around … more

    Apply Now
  19. Senior Flood Risk / Drainage Engineer - Woking - Up to £47k

    Posted a week ago by Matchtech

    Remote job Quick apply
    Salary:
    £40,000 - £47,000/annum Full benefits package
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Senior Flood Risk / Infrastructure Engineer - Woking - Up to £47k. Our client, a leading independent consultancy focusing on infrastructure design, transport planning, flood risk and drainage, are seeking a talented and motivated Senior Flood Risk / Infrastructure Engineer to join their team in … more

  20. Technical Sales Engineer

    Posted a week ago by Best Selection

    Salary:
    £30,000 - £40,000/annum Commission+25 days holiday+Pension
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Technical Sales Engineer. Our scientific instruments industry client is seeking a Technical Sales Engineer. You will focus on generating new business by generating leads and following up thoroughly on all business opportunities to build a profitable portfolio. Requirements:. Experience in Technical … more

    Apply Now
  21. Business Development Executive

    Posted a week ago by Syntech Recruitment Ltd

    Salary:
    £30,000 - £35,000/annum + Bonus
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Business Development Executive. Location: Near Woking, Surrey. Salary: £30,000 - £35,000 per annum (depending on experience. Job Type: Full-time, Permanent. Are you an experienced Business Development Executive with a passion for driving growth in technical sectors? Do you thrive in a dynamic … more

    Apply Now
  22. Field Service Engineer Stevenage base

    Posted 2 weeks ago by Miltenyi Biotec

    Salary:
    £NEG
    Location:
    Woking,United Kingdom
    Job Type:
    Permanent

    Job Description.. If you are passionate about working for an innovative company that provides cutting-edge scientific solutions, join us! Our client base is diverse - we work with hospitals, universities, research institutes, and pharmaceutical companies.. Your role will be to provide excellent … more

    Apply Now
  23. Senior Design Engineers

    Posted 2 weeks ago by Omni Group Ltd

    Salary:
    £50,000 - £55,000/annum dependent on experience
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    SENIOR DESIGN ENGINEER - WOKING. Who we are looking for. People with at least 5 years of design experience and 2 years of management/team lead experience, preferably with a mechanical background. Necessary experience. 5 years design experience. 2 years management/team lead experience. 2:1 BSc or … more

    Apply Now
  24. Design Engineers

    Posted 2 weeks ago by Omni Group Ltd

    Salary:
    £30,000 - £40,000/annum Dependent on experience
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    DESIGN ENGINEER - WOKING. Who we are looking for. People with at least 3 years of design experience, preferably with a mechanical background. Necessary experience. 3 years design experience. 2:1 BSc or BEng in engineering-based course. 2D and 3D CAD experience in Inventor or Solidworks. Preferable … more

    Apply Now
  25. Quality / Welding Inspectors

    Posted 2 weeks ago by Omni Group Ltd

    Salary:
    £35,000/annum Dependent on experience
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    QUALITY INSPECTORS - WOKING. Who we are looking for. People who have a manufacturing/mechanical engineering background, and some knowledge of welding processes. The role can at times be quite physical so applicants should be physically fit. Necessary experience. Manufacturing/mechanical engineering … more

    Apply Now
  26. Business Development Manager

    Posted 2 weeks ago by Omni Group Ltd

    Salary:
    £50,000 - £70,000/annum Dependent On Experience
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    BUSINESS DEVELOPMENT MANAGER - WOKING. Who we are looking for. We are looking for someone who is competent in sales/business development within the Engineering Industry. Necessary Skills/Experience. Business Development. Understanding of Technical Drawings. Full driving licence. About the role. … more

    Apply Now
  27. Senior Design Engineer

    Posted 16/04/2024 by Rise Technical Recruitment

    Salary:
    £80,000 - £90,000/annum Technical & Career Progression
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Senior Design Engineer. £80,000-£90,000 + Technical & Career Progression + Excellent Company Benefits + Growing Business + Training. Woking (Commutable from Send, Guildford, Farnborough, Aldershot, Bracknell, Camberley and surrounding areas. Do you have a background in Optics and are looking to … more

    Apply Now
  28. Head of Research & Development

    Posted 16/04/2024 by Syntech Recruitment Ltd

    Remote job
    Salary:
    £90,000/annum + Bonus + Director Pathway
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Head of Research & Development (Optoelectronics. Starting Salary: £90,000 per annum, with a potential rise within 3 years to Director level. Location: Woking, Surrey (with occasional international travel and remote working. Hours: Full-time, 40 hours per week - Monday to Friday 8:00am - 5:00pm … more

    Apply Now
  29. Lead Planning Engineer

    Posted 16/04/2024 by TRS Staffing Solutions

    Salary:
    £75,000 - £90,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Lead Planning Engineer. TRS Staffing Solutions. Woking, England, United Kingdom (Hybrid. Role: Lead Planning Engineer. Salary: £75k - 90k (Negotiable) Depending on Experience. Location: Woking (Hybrid working. Our client, a global energy services company with over 40 years of experience in oil and … more

    Apply Now
  30. CAD Technician

    Posted 16/04/2024 by Response Personnel Ltd

    Salary:
    £26,000 - £33,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Reporting to the General Manager, you will. Attended site visits to confirm measurements and produce fabrication drawings from those measurements. Liaise competently with clients, engineers and architects to obtain and manage the flow of technical information on projects. Ensure the correct … more

    Apply Now
  31. Infrastructure Engineer

    Posted 16/04/2024 by Aldwych Consulting

    Remote job
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Infrastructure Engineer. Woking, Surrey. Salary: £35,000 - £45,000. Are you an experienced Infrastructure Engineer looking to accelerate in your career? Do you want to join a leading independent consultancy, that prioritises and supports the development of its staff. I am seeking an Infrastructure … more

    Apply Now
  32. Field Service Engineer, Medical Diagnostic Systems

    Posted 15/04/2024 by TRS Consulting

    Remote job
    Salary:
    £43,000/annum
    Location:
    Woking
    Job Type:
    Permanent

    Field Service Engineer, Medical Diagnostic Systems. Basic Salary Up To £43,000. 10% Bonus. Company Car. Pension. Healthcare. Life Insurance. Phone, Laptop. Holidays. * The role will involve working one weekend in four (during this week you will receive two alternative days off work) *. The Role – … more

    Apply Now
  33. Product Support Team Lead

    Posted 12/04/2024 by Omni Group Ltd

    Salary:
    £40,000 - £45,000/annum + Benefits
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    PRODUCT SUPPORT TEAM LEAD - WOKING. Who we are looking for. People who have experience with managing a product support team. Necessary experience. Currently this person will manage 4 people, management experience is important. Engineering or manufacturing experience would be beneficial. About the … more

    Apply Now
  34. PCB Solderer

    Posted 12/04/2024 by ProTech Recruitment Ltd

    Salary:
    £18 - £19/hour PAYE rate + Overtime
    Location:
    Woking, Surrey
    Job Type:
    Contract

    Industry: Electronics. Rate: £18-19 per hour PAYE (Umbrella options available. Duration: 6 months min. Key skills required: PCB Soldering, Surface Mount, IPC-610, IPC-J-Std, Through Hole. Overview. If you are an experienced PCB Solderer looking to work in a high-tech and advanced technology … more

    Apply Now
  35. BIM Technician

    Posted 11/04/2024 by Add Resource & Labour

    Quick apply
    Salary:
    £30,000 - £35,000/annum + 25 days holiday + Bank holidays
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    BIM Technician. Add Resource and Labour – Woking, Surrey. £30,000 - £35,000 Base (depending on experience) + bonus. Monday to Friday. 25 days holiday + Bank holidays + Pension + Life Assurance. The Company…. This well renowned Company is looking to recruit a BIM Technician to assist the successful … more

  36. Maintenance Engineer

    Posted 11/04/2024 by HVAC Recruitment

    Salary:
    £30,000 - £33,000/annum + Package
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Maintenance Engineer. Woking, Mobile basis. Monday - Friday, 8 - 4:30 / 9 - 5. Domestic & Communal Areas. Our client are now looking for a Handyman / Maintenance Engineer to now join the team working on a mobile basis around the Woking and Guildford postcodes. Here you will be working across … more

    Apply Now
  37. MEP REVIT / BIM Technician

    Posted 10/04/2024 by Cotleigh Engineering

    Salary:
    £25,000 - £30,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Revit MEP / BIM Technician (Building Services. Are you looking to develop your career in BIM and Revit MEP Modelling in the Building Services sector working on large scale construction projects. Our Client is currently looking for Junior, Intermediate & Senior level CAD Technicians (with at least 6 … more

    Apply Now
  38. Lead BIM Coordinator

    Posted 10/04/2024 by Cotleigh Engineering

    Salary:
    £35,000 - £45,000/annum Benefits included
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Our client who are a leader in BIM Solutions, having completed more than 2,000 projects over the past 20 years within the construction company. They are looking for an experienced Revit MEP Coordinator to work alongside the Regional Director at their Woking office to help lead/manage projects & … more

    Apply Now
  39. Critical M&E Engineer - Woking - £50,000

    Posted 10/04/2024 by PRS

    Salary:
    £50,000/annum
    Location:
    Woking
    Job Type:
    Permanent

    Critical M&E Engineer - Woking - £50,000. Location: Woking. Salary: £50,000. Hours – Continental Shift Pattern. Our client are a global data centre services organisation, steadily growing their presence, and have a requirement for multiple M&E Maintenance Engineers to be based at a State-of-the-Art … more

    Apply Now
  40. Internal Sales Person

    Posted 10/04/2024 by Engineering Recruitment PDQ

    Salary:
    £31,000 - £38,000/annum Huge Benefits
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    I am looking for a skilled Internal Sales Person (an Account Manager or a Telemarketer or a Telesales person perhaps looking to widen their skills. The company is right out the top draw! Established, outstanding offices, lots of facilities, flex-time start and finish, some work from home, choice of … more

    Apply Now
  41. Embedded Engineer (Control Systems)

    Posted 10/04/2024 by SR2

    Salary:
    £50,000 - £55,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Embedded Software Engineer - Control Systems -Woking - £55,000. Most Embedded Software Engineers are very passionate about their focus in software. It's a fascinating area of software design with lots of nuances. In this opportunity you get to own it. Being part of a small team, you get a lot of … more

    Apply Now
  42. Production Technician

    Posted 09/04/2024 by Faith Recruitment

    Salary:
    £23,500/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Production Technician. £ 23,500. Woking. Our wonderful client are looking for a Production Technician to join their team. The role would be responsible for manual assembly work, record and maintain test and stock records and dealing with shortages effecting due dates. If you have customer service … more

    Apply Now
  43. Maintenance Engineer (Mechanical)

    Posted 08/04/2024 by Alecto Recruitment

    Salary:
    £36,000 - £40,000/annum Benefits
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Maintenance Engineer (Mechanical. £36k-£40k Basic Salary (Fully Employed) + Benefits. Location - Woking, Surrey - Site Based. We currently have a superb opportunity for an experienced and Mechanical bias Operations and Maintenance Engineer to join one of our clients who are a leading provider of … more

    Apply Now
  44. HV Authorised Senior Electrical Engineer

    Posted 08/04/2024 by Alecto Recruitment

    Salary:
    £50,000 - £60,000/annum Benefits
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    HV Authorised Senior Electrical Engineer. £50k-£60k + Benefits. Location - Woking / Surrey - Site Based. Company Background. We currently have a superb opportunity for an experienced Senior Electrical Engineer (Authorised Person) to join one of our clients who are a leading provider of services to … more

    Apply Now
  45. Heat Pump Service Engineer

    Posted 08/04/2024 by Alecto Recruitment

    Salary:
    £40,000 - £50,000/annum Company Van, Benefits
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Heat Pump Service Engineer. £40k-£50k Per Annum + Company Van. Location - Woking / Guildford / Farnborough. Alecto Recruitment Ltd currently has an excellent opportunity for an experienced Air Source Heat Pump / Heating Engineer to join a leading and well established plumbing & heating contractor … more

    Apply Now
  46. Field Service Engineer (Electrical, Gas/Diesel Engines)

    Posted 08/04/2024 by Ernest Gordon Recruitment Limited

    Remote job
    Salary:
    £36,000/annum + Company Vehicle + Door to Door Pay
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Field Service Engineer (Electrical, Gas/Diesel Engines. £36,000 DOE + Overtime OTE 50k + Company Vehicle + Local Patch + Door to Door Pay + Training + Progression + Monday to Friday + Holidays + Pension. Covering Surrey. Are you a Field Service Engineer from a Gas or Diesel Engine background with … more

    Apply Now
  47. Graduate Transport Analysist

    Posted 05/04/2024 by Penguin Recruitment

    Remote job
    Salary:
    £18,991 - £22,444/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    The Company. The Client is a leading Multi-disciplinary in the UK, who specialise in Transport Planning, Infrastructure Design and Environmental Assessments. They work on a diverse range of development projects and schemes, making representations for Local Plans, inform masterplans and support … more

    Apply Now
  48. Data Centre Engineer (IT/Networking)

    Posted 04/04/2024 by Resourcing Group

    Salary:
    £40,000 - £41,000/annum +10% bonus, OT, healthcare, pension
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    My client has an excellent opportunity for a data centre engineer to join their team on a permanent basis. The company are looking for somebody who is keen to learn develop and progress within the organisation. This role will be responsible for repairs, physical installations as well as for the … more

    Apply Now
  49. Graduate Engineer

    Posted 04/04/2024 by April Quest

    Salary:
    £25,000 - £30,000/annum
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    A global leader of advanced wireless telemetry equipment used across a variety of industries, primarily oil & gas. Info about what the Graduate Engineer role entails. Opportunity to travel to unique locations around the globe. Commissioning of electro-mechanical systems at domestic & global client … more

    Apply Now
  50. MEP Revit Technician

    Posted 03/04/2024 by Energi People

    Salary:
    £35,000 - £45,000/annum pension, private health
    Location:
    Woking, Surrey
    Job Type:
    Permanent

    Our Client, a Building Services Design Consultancy is currently looking for a Revit MEP Technician on permanent bases. The company has a wide and interesting project portfolio, including residential, commercial, educational, historical, industrial, leisure, marine, health and energy sectors. Skills … more

    Apply Now

Register & Quick Apply

Passwords must contain at least six characters

As part of the CV-Library network, your CV will be uploaded to CV-Library's database, allowing you to be searched by thousands of potential recruiters and employers. By registering with Engineering Jobs you agree to our Privacy Policy and Terms & Conditions