Please do not post raw binary to Usenet.

There are well established ways to do this, and most
newsposting software will automatically use them for
binary files. Whether binaries should be posted here
at all is a separate issue; some may object to that as
well.

The hjsplit software may split binary files, but it appears
to generate a collection of smaller files that are still
considered binary on most operating systems, and definitely
outside of the standards (RFC's) for Usenet.

To attach your files, even those output by hjsplit, use
standard attachment techniques.

Clue: if there is not a "mime type" in the headers created
when you attach your binary data, you haven't done it
properly.