What kind of steel is this? (lathe tool)

and so I have seen the light, as well as a two piece drill being made... I apologize for my Cali frontier statement and have been educated...

thanks for the vid.
 
We don't mind the disagreements, but name calling is not permitted and or tolerated on this forum. Consider yourselves warned. Apologizing is a good start at this point. Thank you.
 
As others have said, probably carbon tool steel, and it WILL hold an edge, in fact, it is one of the toughest tool steels there is, but it has one huge disadvantage, if it is allowed to get at all hot whilst cutting, it will immediately soften and lose the edge, so reharden it, grind it gently to sharp, touch it up with an india stone then use it with bags of coolant, and it will cut even chilled cast iron. The advantage of HSS is that it can be used almost glowing without loosing its hardness, but it is more difficult to get a perfect edge on. Remember when you heat it for hardening, you must heat to the curie point (where it stops being magnetic) and then hold it at that temp for 20 minutes per inch of thickness, so say it is 1/2" thick, keep ot above curie for 10 minutes, then quench as above, start with oil, then try water if that doesnt work. A file will tell you if you are getting there! I have got a lot of carbon steel lathe tools that I have picked up in box lots at auctions, many of them obviously made from old files, that have been softened, beaten to shape, then re-hardene. They cut!
 
My small bore threading and boring tools are made from O1 tool steel. I just heat till not magnetic, quench in oil, and use it that way. I know you're supposed to temper after hardening but every attempt I made just annealed it again. I don't have any special equipment other than an OA torch, ND motor oil and two eyeballs. They hold up well if not overheated.
 
AND!!! don't forget to temper it as well! brighten the cutting end up, and then heat the other end gently till the cutting end gets to a medium straw colour, and allow it to air cool!
 
Thanks all. I found some of the hardening instructions a little intimidating. I may yet try to harden this at some point, but new 1/4 x 1/4 HSS blanks showed up, AND I got myself a grinder, so I made a little boring bar “from scratch” and it worked quite well!
 
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