Question

In the beginning of the Rockwell hardness experiment, the reading dial is set to _____

(a) 100

(b) 50

(c) 0.1

(d) 0

The question was asked during an online exam.

My query is from Aircraft Materials in section Testing Aircraft Materials of Aerospace Materials & Processes

Answer 1

The correct choice is (d) 0

To elaborate: The dial on the Rockwell hardness test method is where the value can be found. There are two sets of numbers on the dial, black and red. Before the major load is applied on the test specimen, the direct reading dial on the machine has to be fixed to zero.