EDM

Electric Discharge Machining. It is simply a spark between a wire and a workpiece. It does super precise cutting and small hole drilling in electrically-conductive materials.

About

• Uses 0.25 mm brass wire for cutting, Mcmaster has 0.5 mm wire - $30/lb - [1]
• Voltage is 50-300V. Current for 1" cut below is 35A.
• 1 pound of wire used per hour to cut a 1/2" hole in a 3" piece of hard metal. - [2]

BOM

• EDM wire - $40 for 6 lb - [3]

YouTube

• DIY, cuts 1" stainless at 2 mm/min - [4]. Howto - [5]

Resources

• There are many EDM DIY builds out there.
• There's a book on DIY EDM machines - [6]. Youtube - [7]. Books and circuit boards are available - [8]