35 Interview Questions For A Mechanical Design Engineer

Updated 13 February 2023

Mechanical design engineers study, design and create prototypes for new systems and products. When hiring for such roles, interviewers typically ask different types of questions to test a candidate's technical and soft skills. By preparing for these interview questions, you can portray your knowledge confidently and demonstrate that you have the required skills for the job. In this article, we provide general, background and in-depth interview questions for a mechanical design engineer and explain how you can answer some additional questions.

10 General Interview Questions For A Mechanical Design Engineer

Hiring managers ask general interview questions for a mechanical design engineer to understand more about a candidate's application, qualifications and career goals. These questions usually occur at the beginning of the interview and can help you discuss unique aspects of your career and personality:

How did you become interested in mechanical design engineering?
What are your three most significant professional strengths?
What do you consider your biggest weakness?
What are your professional goals for the next five years?
What salary expectations do you have?
What are your hobbies and interests outside of work?
Are you willing to relocate for this job?
When is the earliest you can start working?
Why do you want to leave your current job?
What do you wish to learn while working here?

10 Questions About Experience And Background

An interviewer typically asks questions related to a candidate's professional experience, past jobs and educational background to determine their suitability for the role. Here are some questions you can expect:

Have you managed or trained other team members?
What skills are essential for a mechanical engineer, and do you possess them?
In what ways do you use engineering skills for tasks outside of work?
Do you have experience using digital tools and software to create designs?
What do you consider your most significant professional achievement?
Have you completed specialised training sessions, professional development programmes or certifications?
What is the most challenging project on which you have worked?
Describe a situation where you used data and analytical skills to solve a complex problem.
How do you learn about new engineering trends?
Explain some vital features of a design blueprint.

10 In-Depth Questions

Recruiters generally ask in-depth interview questions to assess your knowledge of engineering and design concepts. These questions usually pertain to specific design engineering terms or tools. Here are some to consider:

Define a stress-strain curve.
What is wireframe modelling, and what are its benefits?
Name different types of screws and fits.
What is the least count?
Explain static and fatigue loading.
What is a datum plane?
Define knurling and its uses.
What is the meaning of the term fit, and what are its different types?
What is the use of a double pulley?
Explain the differences between projectile and rocket motion.

5 Interview Questions With Sample Answers

Here are some more interview questions hiring managers may ask mechanical design engineers, along with their example answers:

1. Explain different types of views used in engineering drawings

Mechanical design engineers prepare detailed blueprints for systems, machines and projects that contain different aspects of the product. By asking this question, the interviewer may assess your understanding of basic elements in engineering design. In your response, you can explain different types of views and why they are important.

Example: 'Engineering designs use many views to convey the interior construction of machine systems and products and how they work. Sectional views focus on one aspect of the drawing, such as the assembly or offset section views. The purpose of section views is to allow the reader to analyse a particular part of the model. Similarly, the projection view shows the 3D model in a 2D view from each side. The isometric view represents 3D objects in 2D. Then, the detailed view allows you to magnify a complex or intricate part of the drawing.'

2. Define the factor of safety

Ensuring the safety of envisioned product prototypes or systems is a key responsibility of a mechanical design engineer. There are several aspects of security to consider, one of the most important being the factor of safety. With this question, the hiring manager is testing your knowledge of mechanical design concepts. In your answer, define the term, discuss its significance and explain how to calculate it.

Example: 'Factor of safety, or FOS, is the actual capacity or strength of a system that is higher than the intended load. The FOS value represents the load-carrying capacity of a system as compared to the expected load usage. To calculate the FOS, you can divide the yield stress by the working stress. The value of FOS is always more than one, as you calculate it according to the design load's maximum value.'

3. What is engineering tolerance?

Tolerance is an important mechanical design concept that helps account for variation in systems. Explaining this term and discussing related concepts can show your expertise and impress the interviewer. Define the meaning of tolerance and describe its importance in your answer, and briefly talk about stack-up analysis.

Example: 'Engineering tolerance represents the permissible variation of dimensions in a system. Tolerance helps calculate the total degree by which you can change the dimensions without impacting the product's intended function. It is important to determine tolerance, as it can be expensive to produce different parts of a system without it. To reduce rejection rates and manufacturing costs, engineers provide the tolerance values of each part in a system.

Tolerance can be of different types, such as linear or geometric. In object dimensions, there are limit, unilateral and bilateral tolerances. Another crucial aspect of tolerance is conducting stack-up analysis, which determines the cumulative effect of tolerances on different parts during assembly. This can help improve the product assembly and account for allowable variations from the given dimensions.'

4. Tell me about your experience overcoming a complex engineering challenge

Mechanical design is a complex and highly technical field that requires multi-disciplinary knowledge. With this question, the interviewer wants to discuss your work on projects that did not work as designed, how you overcame challenges and your problem-solving process. In your answer, you can convey many technical and soft skills and demonstrate your ability to learn from mistakes.

Example: "In my previous job, my team worked on a crucial project to enable a client to operate machines remotely. It was a very exciting project that used several new technologies, but the team struggled during the initial stages of conceptualising and designing the right product. Instead of presenting the client with an ineffective solution, we decided to spend more time studying other tools and collecting data about different approaches. The team leader was extremely driven and helped everyone stay motivated.

This experience helped me realise the importance of teamwork and strong leadership. Once everyone on the team started communicating and collaborating, the work became easier, and we created a prototype that pleased the client. I am glad I have gained more knowledge and improved my communication and organisational skills since then."

5. Explain the process of estimating the cost and timeline for a new design

Engineers often work with clients to create the scope of projects and prepare budgets. Knowing how to balance aspects such as time, cost and quality can help you plan and implement a project. In your response, mention various important factors for project estimation and how you negotiate these aspects with clients.

Example: "The most significant factors that determine a design's cost and timeline are its complexity and size. I usually refer to similar past projects, the client's requirements and the overall risk assessment when deciding the scope. I have presented these estimates to clients multiple times and convinced them to increase the budget limit or scope for business requirements. Furthermore, I am adept at creating budget analysis reports that communicate complex processes and information in a reader-friendly manner."