100 Most Asked Mechanical Engineer Interview Questions with Answers

Here are the top 10 most asked mechanical engineer interview questions along with suggested answers that will help you prove you are the right person for the job.

1. Tell me about the first thing you designed.

The interviewer wants to find out about your early design work to understand how long you have been interested in mechanical engineering. This question gives you an opportunity to show your passion for mechanical engineering and to show how you have been designing and problem-solving for a long time. Your answer should explain your history of designing and problem-solving. Talking about your early designs, even if those were as simple as building things from household items, allows the interviewer to gain an understanding of your history with mechanical engineering and your thought processes.

I have always had an interest in designing and building. Toy cars were my favorite when I was little, but I would get frustrated at the lack of functional steering. I spent hours dismantling my cars and trying to work out how to create and incorporate an axle and get the car to turn right. When I finally got it to work, the sense of achievement I felt was overwhelming. It inspired me to keep designing, keep solving problems, and to work on different projects, including taking part in a design competition as part of a team in high school. All of this eventually led me here.

2. What skills do you feel are most important for a mechanical engineer?

This question gives you an opportunity to show that you understand the role you are interviewing for. It allows the interviewer to assess how your skills would fit within the company. There are many skills you can highlight, such as technical skills, analytical and problem-solving skills, creativity, excellent communication, or sound knowledge of engineering essentials. Whichever skills you choose to emphasize, explain the connection between those skills and the role you are interviewing for. By doing this, you show the interviewer you have considered and understood the role, and you have some self-awareness about what skills you can bring to the job.

A mechanical engineer has to have many skills, but I consider a large part of what I do to be about problem-solving. Often, solving a particular problem means being innovative, because solving a problem may require you to look at things in a new way and disregard past ideas that didn’t work. So problem-solving and innovation are important skills for a mechanical engineer. Along with these skills, a mechanical engineer must have excellent communication skills to explain those innovative ideas clearly to the team and to get the team on board with the idea. I consider those skills to be three of the most important skills for a mechanical engineer.

3. Thinking about the tasks you undertake as part of your current role, which tasks do you prefer?

The interviewer is looking for an answer that shows that the tasks you enjoy doing are the main ones called for as part of the role you are interviewing for. Before the interview, familiarize yourself with the job description and consider the tasks the company will require you to perform as part of the role. Identify which of the tasks are the key ones. Use your answer to highlight the overlap between your preferred tasks and the key tasks of the role.

The tasks I prefer are building prototypes, testing them, and then making any required changes. Seeing the result and knowing that my design has solved the problem is what I enjoy most, but you can’t get to that point without using prototypes and testing and tweaking them until they do exactly what the project needs. I also really enjoy the practical application of the theory and bringing the theory to life, although of course, without understanding the theory, you can’t properly perform the practical aspects.

4. Tell me how you would explain complex designs to someone working in another industry.

The ability to explain complex designs to a layperson or those working in other industries can be a valuable asset to an employer. It shows excellent communication skills to be able to break complex designs and ideas down into easy-to-understand language for others to understand. That skill can be useful in assisting current clients with problems and for helping win bids with new clients. Marketing teams can fulfill their role of marketing the product if they understand the product you are designing and its purpose. It also shows your ability to work well as part of a team and being able to cooperate with others. All these benefits make this an important skill to show during the interview.

Whenever I explain a complex design to a layperson or to someone who doesn’t have an engineering background, I would avoid using technical language and acronyms as much as possible. If I had to use technical language, first I would explain the term, unless the person showed that they already understood it. I think it is also helpful to share the purpose of the design so that others can understand the problem we are trying to solve. I would then talk through how the design achieves its purpose. I want to create a map for them to see how we get from the problem to the solution that I am designing. Allowing the person or team to ask questions if they don’t understand is important, as is asking if they follow what I am saying. What might seem straightforward for someone with a mechanical engineering background may not be straightforward for someone without that background, and it is important to check in with them throughout the explanation.

5. What computer programs and software do you have experience using?

Mechanical engineers use a variety of programs and software. The interviewer is looking to understand how familiar you are with different software. They will also consider whether the programs and software you have used align with those the company uses so that they can assess any possible training needs. Before the interview, research the company and find out what type of programs and software are likely used. Also, be sure to check the job listing specifically for that information. If you are familiar with or have used programs and software that you think or know the company uses, be sure to emphasize this in your answer.

I have experience with different programs and software. I have used many types of CAD software, including Revit Structure and SolidWorks, although my preferred CAD software is Autocad 3D. I’m familiar with all the Microsoft Office products and have significant experience using Excel and Visual Basic to automate Excel files. For structural analysis, my preferred product is Safe, although I have also used Staad Pro.

6. Can you explain the different types of fits?

The interviewer is testing your technical knowledge. Technical questions are common in mechanical engineering interviews, although the difficulty of the questions will depend on the knowledge of the person interviewing you and the role you are interviewing for. Before the interview, familiarize yourself with the job description and consider what technical knowledge you need to perform the job.

There are three groups. The first is clearance fit. The diameter of the smallest hole is larger than the largest shaft diameter, allowing the two parts freedom or clearance to move relative to each other. The second is interference fit. Two tight-fitting parts create a joint held together by friction created by pushing or pressing the parts together. The third is transition fit, which is a compromise between the first and second groups of fit. There may be either a small amount of clearance or interference.

7. Have you gained any new engineering skills recently? If so, tell me about this.

The interviewer is trying to understand if you are a self-starter and driven to continually learn and improve on your skills. By showing you have an interest in learning new skills, you are showing your commitment to the field of engineering, to continuing to improve and expand your skillset, and to staying up-to-date in the field. Learning new skills also shows you are adaptable, an important quality to have.

Last year, I completed a course on designing solar collector systems. Society is becoming increasingly conscious of renewable energy sources, and solar energy is becoming more popular as part of that increased awareness. That was the reason I took the course. The course helped me understand how solar collector systems generate energy and allowed me to learn about the components of the systems. Those skills will become more relevant as people and businesses continue to move towards renewable energy sources.

8. Can you explain the similarities between the pneumatic system and the hydraulic system? Which would you use, if you had a choice?

The interviewer is testing your technical knowledge of pneumatics and hydraulics and the benefits and drawbacks of the different systems. They want to know that you understand both types of systems and can justify why you would choose one over the other.

The systems are similar as they both use pressure, with pneumatics using gases, while hydraulics use oil or water. If everything else was neutral, I would choose pneumatics. Pneumatic systems are cheaper and move faster. If they leak, they are less messy than a hydraulic system, which would leak oil or water. For those reasons, I would use pneumatics over hydraulics, but each project is unique, and other factors may make hydraulics the preferred system for a particular project.

9. Can you tell me about a time you worked on an engineering project that failed?

It is hard to admit to a failure, but the interviewer understands that admitting mistakes and learning from them shows an engineer who can be open, honest, and has the potential to improve. This question allows you an opportunity to show the interviewer that you can cope with mistakes and tackle them professionally. Your answer should focus on the lessons you learned from the failed project and whether the project reached an eventual successful conclusion.

I was involved in designing a wheelchair for transporting patients that would be easy for staff to push and maneuver. The purpose was to improve the design of the outdated wheelchairs being used. We created a wheelchair that was much lighter and easier to maneuver, but we hadn’t been told that the wheelchairs would transport morbidly obese patients. That meant we needed to use materials that could withstand more weight and pressure on the joints. The prototype didn’t take that into account. We discovered this during the testing phase when we stress-tested the joints. We then had to go back to the design and revise our plans, resulting in increased cost and time. We had made certain assumptions during the design phase, and next time, I would ask extra questions to ensure the assumptions were accurate. I would also consider widening my design envelope on critical functionality such as weight and pressure to give the product more flexibility.

10. Explain what a process flow diagram is.

The interviewer is seeking to test your technical knowledge. Show your technical knowledge by briefly explaining what that kind of diagram is and how it is used. Be prepared for follow-up questions if the interviewer is looking for more information.

A process flow diagram is a diagram or sketch used to show the general flow of industrial plant processes and equipment. It focuses on the major equipment, not the minor details. The sketch describes the equipment, product flow, connections, and relationships between the components.

Next 90 Most Asked Mechanical Engineer Interview Questions

  • Tell me about yourself.
  • What do you consider to be your main strengths?
  • Tell me about your weaknesses.
  • What do you enjoy most about working as part of a team?
  • Why did you study mechanical engineering?
  • What do you know about our company?
  • Do you have any patents?
  • What is your biggest professional achievement to date?
  • Describe a time you used data to support a decision you made.
  • How do you prioritize projects?
  • Tell me about your education.
  • When doing routine engineering work, how do you avoid becoming bored?
  • Tell me about your career goals.
  • Have you ever failed to deliver a project on time? How did you handle that?
  • Tell me about a time you disagreed with a colleague. How did you resolve matters?
  • What is your most successful engineering project?
  • Describe a time you used logic to solve a problem.
  • How do you cope with pressure at work?
  • When was the last time you had to use your initiative?
  • How do you check a project for flaws?
  • Have you ever suffered a setback at work? How did you handle that?
  • Do you prefer to work alone or as part of a team? Why?
  • Another engineer disagrees with your design in front of your team. What do you do?
  • Have you ever had to make a decision without all the information you require or would like? How did you arrive at your decision?
  • What is your least favorite task in your current role?
  • Have you ever experienced difficulties in explaining a project to a non-technical person? How did you overcome those difficulties?
  • A 9-year-old asks you what you do as a mechanical engineer. How would you describe your job to him or her?
  • How do you keep up-to-date with the latest trends in your field?
  • Do you prefer to solve problems with your hands or your head?
  • How would you define teamwork?
  • How would you describe your communication style?
  • What obstacles have you had to overcome in your career?
  • Describe a situation where you used your mechanical engineering skills outside of work.
  • What attracts you to this role?
  • Where do you see yourself in ten years?
  • What design project have you learned the most from in your career and why?
  • Tell me how you evaluate the scope of a project.
  • Why should we select you instead of one of the other candidates?
  • Two clients want to work with you. The first is a long-standing client. The project budget is small. The second is a large company that you have never worked with. The company has a large budget. Explain how you would decide which client to work with.
  • What would you hope to achieve in your first six months in this role?
  • What does your ideal working environment look like?
  • A client is being difficult, regularly changing the specifications of the project. What do you do?
  • Have you ever encountered resistance to a project or design? How did you handle that?
  • Can you tell me about a time you discovered flaws in a design after testing? What did you do?
  • Tell me about the second law of thermodynamics.
  • Can you explain what GD&T is?
  • Why is tolerance important in engineering?
  • Can you explain the difference between fatigue and creep?
  • Tell me what type of bearings you prefer.
  • Does stress produce strain or does strain produce stress?
  • Why is a thermostat important in an engine cooling system?
  • Can you explain what a turboprop engine is?
  • What is torque?
  • Why do diesel engines make more torque than their gasoline counterparts?
  • Tell me about the different types of brakes.
  • Is it acceptable to use motor oil in a hydraulic system?
  • Can you explain universal coupling and how it is used?
  • Explain mechanical refrigeration.
  • What are the essential guidelines for designing castings?
  • Explain the difference between metal and non-metal materials.
  • Can you give me some examples of mechanisms?
  • Tell me about P&IDs.
  • Tell me what you know about orthographic drawings.
  • Can you explain the difference between an electric motor and an electric generator?
  • What advantage do you think there is to a double pulley?
  • Can you explain free energy and free enthalpy and their importance?
  • Tell me about cold drawing processes.
  • Explain the purpose of heat treatment.
  • Explain the different types of springs and when you would use each type.
  • Tell me about your most recent design project.
  • Explain the differences between struts and columns.
  • Can you tell me about different types of screws and when you might use each type?
  • Explain wet corrosion and galvanic corrosion. How are they different?
  • What are the advantages of projectile motion over rocket motion?
  • Explain the difference between edge dislocation and screw dislocation.
  • If I heat a steel cable, will it become shorter or longer under load? Explain why.
  • How does a pipe differ from a tube?
  • Explain the difference between continuous beam and conjugate beam.
  • Tell me about theories of failure for ductile materials.
  • What factors promote transition from ductile to brittle fracture?
  • The instantaneous rate of heat flow in the conduction of heat is the product of which three factors?
  • Can you explain the difference between alpha, gamma, and delta iron?
  • What role does nitrogen have in welding?
  • Explain what a cotter joint is.
  • Can you explain the difference between energy conservation and energy management?
  • What is a uniformly distributed load?
  • Can you give examples of metals classified as FCC, CCP, HCP and BCC?
  • What is the role of manganese in alloying steel?
  • Tell me how nuclear fission differs from fission chain reaction.
  • Describe knurling.

10 Best Questions to Ask in a Mechanical Engineer Interview

An interview is an opportunity for the interviewer to get to know you, but also an opportunity for you to learn more about the company. An interviewer will normally give you a chance to ask questions of them at the end of the interview. The questions you ask can help you learn more about the company and are also an opportunity for you to show a genuine interest in the company.

  • What does a typical day look like in this role?
  • How would you describe the culture here?
  • What opportunities are available to expand my skill set?
  • Where do you see the company in five years?
  • What do you think is the biggest engineering disaster?
  • Why do you enjoy working here?
  • What do you consider to be the biggest challenges the company will face in the next twelve months?
  • What do you expect of me in the first ninety days?
  • Can you tell me about the team I would be working with?
  • What do you consider to be the essential skills for a mechanical engineer?

Before the interview, research the company. Follow industry trends. Think about the skills you have and how they align with the role. Be prepared to show you have the right skills and technical knowledge for the role. Make sure you know how to get to the interview location, arrive early, and are appropriately dressed. Bring multiple clean copies of your resume, a pad of paper for taking notes, and a pen. Relax, and don’t forget that personality really does matter. So smile. You can do this!

Author Biography
Keith Miller has over 25 years experience as a CEO and serial entrepreneur. As an entreprenuer, he has founded several multi-million dollar companies. As a writer, Keith's work has been mentioned in CIO Magazine, Workable, BizTech, and The Charlotte Observer. If you have any questions about the content of this blog post, then please send our content editing team a message here.