Question

Cross section
itudinal view
Features​

Answer 1

Answer:

I think

Explanation:

Longitudinal sections from four bolts were examined. The bolts had a sudden transition in cross section and coarse grinding grooves, both of which are liable to decrease the fatigue strength. Longitudinal sections of bolts were prepared from the bolts and examined under microscope. A small crack (0.1 to 0.2 mm deep) was observed in one of the bolts. The other bolts were broken open at the point of cracking. In some bolts, narrow crescent-shaped cracks were observed.

Answer 2

Answer:

longitudanal section from 4 bilts