Blacksmith Gil Ramirez demonstrated how he forged large and impressive steel D20 dice in a two-part episode of his series Vlogsmith. The first video explained the icosahedron shape, and how Ramirez carefully measured out the faces and vertices of the die, and he actually forges the die from a cast iron sphere in the second video.
This is it! In this video I make a 20 sided dice, otherwise known as an Icosahedron. This is the D20 that I made for Felicia Day and gave to her on Table Top Day.