The vintage Greenfield "Little Giant" Tap and Die sets are considered the gold standard of early 20th-century American machining tools. Produced by the Greenfield Tap & Die Corporation (GTD) in Massachusetts, these sets were revolutionary because of their "two-piece" adjustable die design, which allowed for much greater precision than the solid dies common at the time. The set is near complete (some pieces missing) housed in a wooden box. GTD was formed by a merger of the Wells Brothers Company and Wiley & Russell. The "Little Giant" brand was originally a Wells Brothers trademark that became the flagship product of the new corporation. Dates back to 1912.