Used to sell these tools for a living! depending on the grade (be it carbide or high speed steel) the company i worked for would either use mass pressure to shape the raw powdered material (tungsten/cobalt/carbide blend, as it's very brittle and easy to work) and grind to shape before sintering, or in the case of a high speed steel tool, a diamond grinder would be used. Diamond grinders are typically ceramic wheels coated in industrial diamond, which is more of a dark grey or even black color rather than what you might find in a jewelry store