Mechanical Engineering Technical Interview Questions

Top Mechanical Engineering Interview Questions

There’s a wide range of topics that are covered during interviews, but you’ll most often find these fundamental questions covered the most:

Mechanics of Materials (Beam Theory):

  1. What are six ways to reduce cantilever beam deflection?
  2. Given a wall-mounted cantilever beam and a point load at the free end, describe the shear force diagram and bending moment diagram
  3. On which side of a wall-mounted cantilever beam induced with a point load will it fail?
  4. A flagpole is mounted to the ground and an eagle is sitting on top with wind causing the pole to sway back and forth. Describe ways to reduce the amount of motion in the flagpole
  5. If you have an 'I' cross section cantilever beam and you want to make it stiffer, do you increase the height or width?


  1. Label and describe the key points on a stress-strain curve
  2. Describe/draw the stress-strain curve of aluminum vs. steel on the same graph
  3. Describe the stress-strain curve between brittle and flexible materials?
  4. What is the difference between stiffness and strength? - #2 by hardwarefyi
  5. At what region of a stress-strain curve does strain hardening occur? What does strain hardening do?
  6. Rank the strength of the following materials from strongest to weakest: carbon fiber, plastic, steel, aluminum - #9 by hardwarefyi
  7. Describe/draw the stress-strain curve between aluminum, steel, hardened steel, & plastics on the same graph

Physics/Free-Body Diagrams:

  1. If two vehicles are identical, except for one weighing twice as much as the other vehicle, and they roll down a hill, which car reaches the bottom first?
  2. A car on a hill of constant slope accelerates from rest under gravity to a point on the hill. If you want to maximize the velocity of the car at this point, where along the length of the car (e.g. downhill or uphill) would you fix an additional mass?
  3. If I have a solid rod and hollow rod with the same mass and I let them roll down a ramp, which one reaches the bottom first and why? - #3 by hardwarefyi
  4. You put a glass of water on a record turntable and begin slowly increasing the speed. What happens first? Does the glass slide off or tip over, or does the water splash out?

Additional Questions:

  1. Archimede’s Principle: You are in a rowing boat on a lake. A large heavy rock is also in the boat. You heave the rock overboard. It sinks to the bottom of the lake. What happens to the water level in the lake? Does it rise, fall or stay the same?
  2. High-Level Thermodynamics: A refrigerator is in a room and you open the door. Will the room get colder or hotter?
  3. Heat Transfer: What are the three different modes of heat transfer?

Important engineering fundamentals to review include:

  1. Mechanics of Materials (Beam Theory)
    • Cantilever beams, stress equations, buckling, fatigue life
  2. Materials
    • Stress-strain curve
    • Material properties for common plastics & metals
  3. Manufacturing Processes
    • Injection molding for plastics
    • Metal manufacturing - forming, stamping, additive (i.e. die-casting) and subtractive (i.e. CNC machining) processes
  4. Free Body Diagrams

If you’re preparing for interviews, we offers resources to help accelerate your career in hardware!

  1. Engineering Fundamentals Interviewing Cheatsheets
  2. Hardware FYI - Mechanical Engineering Interview Crash Course