Mechanical CAD Designer

SII Group delivers Digital Services, IT, Engineering, and Consulting to diverse industries, enabling digital transformation through our commitment to Growth, People, and CSR.

With over 16,000 professionals across 21 countries, we're recognised as a "Great Place to Work" for fostering a high-trust culture. Our core values of Trust, Transparency, and Quality drive our work package delivery, ensuring we meet and exceed client expectations as a committed partner.

Since 2016, SII UK has supported top Aerospace & Defense, Aviation, Transportation, and Finance clients, empowering digital transformation with industry-leading engineering expertise.

Let's Tech Together is our promise to encourage innovation and teamwork. We support our engineers with development opportunities and a collaborative, inclusive environment where every voice is valued and empowered.

THE OPPORTUNITY
A Mechanical CAD Engineer is required to join a team responsible for developing and maintaining mechanical designs for an established product line within a multinational Defence company. This role involves both the creation of new designs and the modification and update of existing ones. The position is based at the Client's site in Crawley, but has a hybrid working situation. The ideal candidate: 3–5 years of experience in mechanical design, ideally within the Defence or Aerospace domain Hands-on experience with mechanical design tools and practices Proficient in using 3D CAD tools Understanding of mechanical design lifecycles and related documentation Able to interpret legacy drawings and documentation to support updates and improvements Works independently once familiar with the project scope and tools Maintains strong configuration control of design baselines Collaborates effectively with systems, manufacturing, and quality teams Familiar with tolerancing, materials selection, and design for manufacture and assembly (DFMA) principles.

KEY RESPONSIBILITIES:

• Create and modify detailed 3D models and 2D drawings in line with project and defence standards
• Ensure updates are correctly integrated into the design baseline, supporting configuration management Interpret requirements and translate them into mechanical design solutions Investigate legacy design data to support rework, updates, or enhancements
• Support prototype builds and design verification activities
• Maintain and update Bills of Materials (BOMs) as required
• Liaise with suppliers and internal teams to resolve design-related issues
• Attend daily stand-ups and report progress and blockers
• Support the integration of mechanical designs with other disciplines (electrical, systems)

EXPERIENCE AND SKILLS:
Essential:

• 3–5 years of experience in a mechanical CAD engineering role
• Experience in Defence, Aerospace, or other regulated industry sectors
• Proficient in at least one mainstream 3D CAD tool (e.g., NX, SolidWorks, Creo)
• Familiarity with configuration and change control processes
• Comfortable working with legacy data and reverse engineering techniques
• Understanding of mechanical tolerancing and material properties
• Autonomous and organised, with strong attention to detail
• Familiar with relevant standards
• Team-oriented, communicative, and professional in a client-facing environment Desirable:
• Current or recent UK Security Clearance (SC); security-cleared candidates will be well-positioned for this role
• Exposure to design verification and validation activities
• Knowledge of manufacturing processes (CNC, sheet metal, casting, etc.)
• Awareness of thermal, shock, and vibration considerations in mechanical design
• Familiarity with drawing control and release processes in defence programmes
• Experience with FEA or design analysis tools

Diversity & Inclusion:

We are committed to building an inclusive and diverse workplace. Applications are strongly encouraged from women, individuals from minority backgrounds, and candidates from non-traditional engineering routes. If you meet most but not all of the listed criteria, we still welcome your application.

Values & Behaviours:

• Customer-focused mindset.
• Strong collaboration and teamwork skills.
• Ability to innovate and think critically.
• Analytical mindset for solving complex technical problems.
• Self-motivated with a proactive approach.
• Strong interpersonal skills, capable of working in a multidisciplinary environment.
• Ability to manage workload, prioritize tasks, and work under pressure to meet deadlines.

BENEFITS:

• Competitive Basic Salary
• 6% Employers Contribution + 6% as a salary sacrifice
• Private Medical Insurance, Life Cover and Income Protection
• 25 days holiday
• 5 days full sick pay per year
• Flexible working
• Cycle to Work & TechScheme
• Continuous professional development
• Corporate access to the Udemy platform
• If you're applying for a role requiring security clearance, please be aware that foreign or dual nationality is not an automatic bar, however certain posts may have restrictions which could affect those who do not have sole British nationality or who have personal connections with certain countries outside the UK.