Which of the following has open structure?
C 8 K 5 3 17
A 80 K 4 B 17
A 46 K 5 B 17
C 600 K 8 B 17
Correct Answer: D — C 600 K 8 B 17
Explanation:
Fourth place of ISO designation of the grinding wheel represents Structure and “8” comes under open structure.
