The CAN/CSAB149.1 Natural Gas and Propane Installation Code Section 6.2.5 states that, “Flared nuts shall be forged.”
But with so many imitations out there, how do you know if you are buying genuine forged flare nuts?
Unfortunately, the North American market has been flooded with sub-standard imitations of forged brass flare nuts.
Unfortunately, the North American market has been flooded with sub-standard imitations of forged brass flare nuts. Imitation forged fittings are made by screw machining UNS C37700 forging brass bar or stamping non UNS C37700 material. The resulting brass fitting may appear similar to a real forged fitting, but because the blanks were not heated (stress relieved) twice, imitation forgings are prone to season cracking and cracking from installation torque.
A genuine forged brass flare nut has a contoured body shape and uniform grain whereas imitation forged fittings often have machining marks on the body and face. Many are bright dipped (brass plated) or shot-blasted to disguise these marks.
But despite all these tell-tale signs, some imitations are still visually good enough to get past even the experts. That’s why all Fairview “Genuine Forged” Flare Nuts are marked “C37700” right on the fitting body for your guaranteed peace of mind.