According to Indian standard specifications, plain carbon steel designated by 40 C8 means that the carbon content is

A. 0.04%

B. 0.35 to 0.45%

C. 0.4 to 0.6%

D. 0.6 to 0.8%

Answer: Option B

Solution(By Examveda Team)

Carbon steel - carbon range 0.35 to 0.45%
40c8 actually gives you the carbon and manganese value in the steel.
this designation is mostly used for plain carbon steels.
It's a percentage of Carbon (letter C) in the steel.