I just saw this interesting YT video that claims to double the life for HSS drill bits by applying a cryogenic treatment. I wonder if this would work for HSS endmills or if it would make them too brittle when applying sideloads.
I am not a metallurgist but I think the cryo treatments only work for certain types of metal compounds. I turn on my lathe and the M4 steel gets a lot of cryo treatments. The M4 and other modern HHS lathe tools start as powdered components so it can be mixed very precisely before melting and melding of the various components. The cryo process is precisely controlled for the type of metal and the temperature.
So not sure if regular HHS would benefit from any cryo treating or if the process is just too expensive to make it feasible for the cheaper bits.
Cool video! But my understanding is that even COTS M42 (cobalt) steel is significantly more durable (and expensive) than M2 HSS, but still only ~1/3 as stiff and significantly less durable than solid tungsten carbide.
In the video, the bits used are run of the mill HSS drill bits. It would be surprising that they would be of the right alloy. While HSS are generally not as durable as carbide, they cost less and @Vince.Fab uses them successfully for aluminum work. The question however is the cost of treating them since it is not easily done but one entrepreneurial artisan could have a setup and sell the product since it probably would cost the same to treat 1 or 50 bits at once.