eGigMechanical engineer interview questions and answers
Mechanical interviews mix core subjects with plant work: production, maintenance, quality and safety. Be ready to talk about your project or plant training in detail.
12 questions. Read each one, start the timer and answer out loud as if you were in the room, then open the tip. Nothing is recorded.
Tell me about your project or plant experience.
What a good answer covers
What the machine or process was, your role, a problem you solved and the result.
What is the difference between stress and strain?
What a good answer covers
Stress is force per unit area. Strain is the change in length divided by original length. Within the elastic limit, stress is proportional to strain.
Explain the four strokes of an engine.
What a good answer covers
Suction, compression, power and exhaust, completed in two turns of the crankshaft.
How is a diesel engine different from a petrol engine?
What a good answer covers
Diesel ignites by compression with a higher compression ratio; petrol uses a spark plug.
What are the main heat treatment processes?
What a good answer covers
Annealing to soften, normalising to refine grain, hardening by quenching, and tempering to reduce brittleness.
What are tolerances and GD&T?
What a good answer covers
Allowed variation in size, and symbols that control form, orientation and position on drawings.
Preventive or breakdown maintenance: what is the difference?
What a good answer covers
Preventive maintenance is planned to avoid failures. Breakdown maintenance happens after a failure. Predictive uses data to act just in time.
What are 5S and Kaizen?
What a good answer covers
5S: sort, set in order, shine, standardise, sustain. Kaizen is small, continuous improvement by everyone.
What is OEE?
What a good answer covers
Overall equipment effectiveness: availability × performance × quality.
How do you find the root cause of a problem?
What a good answer covers
Collect data, then use 5 Whys or a fishbone diagram, fix the cause and check it stays fixed.
Which CAD tools have you used?
What a good answer covers
AutoCAD, SolidWorks, CATIA or Creo. Mention a part or assembly you modelled.
How do you keep the shop floor safe?
What a good answer covers
Machine guards, PPE, lockout-tagout during maintenance, and training.
All 12 questions with answers
1. Tell me about your project or plant experience.
What the machine or process was, your role, a problem you solved and the result.
2. What is the difference between stress and strain?
Stress is force per unit area. Strain is the change in length divided by original length. Within the elastic limit, stress is proportional to strain.
3. Explain the four strokes of an engine.
Suction, compression, power and exhaust, completed in two turns of the crankshaft.
4. How is a diesel engine different from a petrol engine?
Diesel ignites by compression with a higher compression ratio; petrol uses a spark plug.
5. What are the main heat treatment processes?
Annealing to soften, normalising to refine grain, hardening by quenching, and tempering to reduce brittleness.
6. What are tolerances and GD&T?
Allowed variation in size, and symbols that control form, orientation and position on drawings.
7. Preventive or breakdown maintenance: what is the difference?
Preventive maintenance is planned to avoid failures. Breakdown maintenance happens after a failure. Predictive uses data to act just in time.
8. What are 5S and Kaizen?
5S: sort, set in order, shine, standardise, sustain. Kaizen is small, continuous improvement by everyone.
9. What is OEE?
Overall equipment effectiveness: availability × performance × quality.
10. How do you find the root cause of a problem?
Collect data, then use 5 Whys or a fishbone diagram, fix the cause and check it stays fixed.
11. Which CAD tools have you used?
AutoCAD, SolidWorks, CATIA or Creo. Mention a part or assembly you modelled.
12. How do you keep the shop floor safe?
Machine guards, PPE, lockout-tagout during maintenance, and training.
Before the interview
- Read the job description twice and match two of your examples to what it asks for.
- Keep printed copies of your resume, ID proof and certificates ready, even for online rounds.
- Know your current CTC, expected salary and notice period. Check typical pay in our salary guide, and compare offers with the in-hand salary calculator.
- Genuine employers never ask you to pay for an interview, training kit or joining. Report anyone who does.