file extraction of unknown file type problem

[2chile]

I've downloaded several files that represent ISO of game. No idea what type files they are as their extensions begin with .001 and progress higher (.002, .003 ...) with .001 the lowest. What I did try but doesn't seem right, is renaming to rar files (.001 to .rar, .002 to r00 and so forth. I then began extracting with WinRar and noticed they were combining into a .bin file which is familiar to me. Can this method be correct or could someone explain what type of file I began with and the proper way to extract with what program.
Thanks for any help