Draw a 42 mm equilateral triangle on a 6 mm thick infinite board.
Draw common sided triangles next to existing ones across the entire board.
Draw a 41.6 mm circle at each triangle corner.
Punch through each circle at a 40 degree inward taper, from both sides of the board,.
Punch a 6 mm round hole at the center of each triangle.
Cut to shape perpendicularly between two adjacent small circles.
A board, six mils thick,
Triangles touch, circles pierce,
Tapered holes unite.
