[CAT315C]

Originally Posted by Hemi1966

Those are made with keyway broach. The set I got can you do 2 and 3mm keyways in to 6,8 and 10mm holes.
It's not that expensive: https://www.wabeco-remscheid.de/keil...adeln-hss.html

You also need some kind of arbor press to push the tool through the gear.

If you have a lathe can also make channels for braces, I do not believe it was possible, but I ended up witnessing with my own eyes the operator making the key a pulley / shaft

Just make a tool in the channel width and entering decimal measures to the channel.

Note:. Power off.