I have just engraved a sword forged by a friend of mine . It was a 12th century sword replica, my choice was the “uncialeâ€, used at the same period :
http://www.collegecuallacci.com/musique/educmusique/docs/onciale.jpg
You can see the result here: The steel was miserably hard, I broke my tungsten carbide tip a lot
https://www.youtube.com/watch?v=DME7K2euXlM