What program do you use to check for bad sectors?

Just bought 5 used 8TB Ultrastar drives on ebay for only $35 each. Heck of a deal right? Checked smart info and everything looks good. Of course i know it would be a good idea to do a complete scan for bad sectors but I don’t know the best program for that. Ideally a free win10 program that i could test all 5 at once connected to one pc