This is probably not a Stuffit archive. Usually, they have a .sit extension. Stuffit hasn't been in wide use since the early 2000's. Unless you're working with a really old file intended for a Macintosh, the chances that the file needs Stuffit Expander are slim.
You may actually just have a binary file with that extension. Try
unzip on the file in question.
But can you provide more details like... What is the filename? Where did it come from? What is it intended for?
In linux, try the command
file filename.bin - That should give you a (possibly) detailed description of the file type.
$ file phys113.sit
phys113.sit: StuffIt Archive
$ file ilo2_207.bin
This actually appears to be a Stuffit file. Download the Stuffit binary and decompression utility for Linux from here.