Most jackhammer bits are not red hard. And they do not spark that way. I received a broken pavement breaker bit from a blacksmith who "qualified" it as red hard. It wasn't, but I found that out after the tool I made from it failed. The steel turned out to work fine for less demanding applications, with a water quench
. This blacksmith sharpened these bits as a large part of his business, but only bought new S-7 for his own tools. He did not recycle broken bits. They were for passing out to the newbies who occasionally visited him...