How It's Made S4E3 High-Precision Cutting Tools, Stained Glass, Semi-Trailers, Recorders

How It's Made Season 4 Episode 3 Online – Hard industrial materials are shaped and sharpened into high-precision cutting tools, colored glass is cut and joined into stained-glass panels, structural components are assembled into semi-trailers, and wood or plastic is bored and finished to make recorders.