Jeweller's hammer. By Sam Towns, Bladesmith. 11:58 video:
https://www.youtube.com/watch?v=9DezoxjEYWE
Previously:
https://www.homemadetools.net/forum/...753#post178795
https://www.homemadetools.net/forum/...343#post173203
https://www.homemadetools.net/forum/...658#post147668
