If you have access to a lathe you can add jimping to a hardened blade very easily.
You need a thin cutting disk, (the ones I use are 4 inches diameter and 1mm thick) and a suitable arbour to mount it in the lathe chuck. I had a cut off saw arbour which fitted and I mount the cutting disk...
I used to struggle to get three holes out of a tap and would often break them. I used to spend hours tapping holes and removing broken taps and dreaded tapping titanium.
Faced with about 320 holes to tap in 1/8 inch titanium I bought a tapmatic head and a couple of very expensive taps. I...