Question

What are the values of thickness of annealed surface obtained while machining using EDM?

(a) 1 to 25 µm

(b) 50 to 200 µm

(c) 200 to 500 µm

(d) 500 to 1000 µm

I had been asked this question in an interview for job.

My doubt stems from EDM-Heat Affected Zone (HAZ) in chapter Thermal Processes of Advanced Machining

Answer 1

Correct answer is (b) 50 to 200 µm

The best I can explain: Values of annealed surface thickness range from 50 µm to 200 µm.