ENG-MARS is a typeface made of single lines that's perfect lasercutting or CNC milling.
Traditional fonts are thick. Standard font formats like TTF and OTF only allow closed shapes, which means characters are formed with outlines, no matter how thin they look. ENG-MARS is formed with single-stroke vector lines, plus, most characters are made of a single curve (two, at most) — and that means the engraving machine won't waste time cutting letters.
Design-wise, ENG-MARS follows a strict set of guidelines: each letter/number fills a 4x8 rectangle and is only composed of circles (4-unit diameter, broken down into orthagonal quarters), horizontal, and vertical lines (2-unit modules).
It comes with a few extra characters (hyphen, plus, quotes), as well as nice calibration-rectangles to be used for scaling and spacing purposes. I recommend one little dash between letters, one big dash between lines, and one skinny rectangle between words.