Density Cubes Set - Includes 6 Metals - Brass, Lead, Iron, Copper, Aluminum, Zinc - 0.4" (10mm) Sides - for use with Density, Specific Gravity Activities - Eisco Labs: Amazon.com: Industrial & Scientific
How those satisfying perfect fit metal cuts are made - video by Steve Mould : r/Perfectfit
Using Multiple Metals to 3D Print the Perfect Gear Cube | metal | Using Multiple Metals to 3D Print the Perfect Gear Cube | By Titans of CNC Machining | Facebook
MetMo Cube: Experience Metal In Motion
MetMo Cube: Experience Metal In Motion
Gaze Upon the Black Magic of Electrical Discharge Machining | WIRED