Miz steel quality

Has anyone used miz steel grade 40 in residential constrcution?
How is the quality of the steel?

Take 3 samples of approximately 1 meter in length and take it to testing lab for steel or take to UET taxila or Lahore or Peshawar and that would give you the real strength of the steel… there is very less difference between grad 40 and 60 steel price so better to buy grade 60…