3D printer build plate for a friend, made from 1/4" mic 6 tooling plate. For an Ender 3, spots for embedded magnets and finger grooves. 235mmx235mm : r/Machinists
Mic-6 Arconic/Alcoa Cast Aluminum Tooling Plate - 1/4" x 12 1/8 x 6 13/16 | eBay
ATP-5 Vs Mic-6: What's Best For Your Business? – Clinton Aluminum