John Duff Limited

John Duff Limited is a family-run custom metal fabrication shop in Petrolia, Ontario (founded 1967) providing shearing, forming, rolling, CNC Hi‑Def plasma cutting, and specialty welding (CWB W47.1 & W47.2 certified); they work in mild steel, stainless, aluminum, copper and brass to produce stairs, platforms, railings, ductwork, truck modifications, made-to-order pipe clamps (2"–60"+), and one-off custom projects for industrial, construction, manufacturing, commercial and agricultural clients while emphasizing skilled tradesmanship, local relationships, and community involvement.