The Brass Flare Fittings provide reliable leak-free connections for high-pressure fluid and gas applications. Flare fittings are offered in 37Â° flare, 45Â° flare, and 90Â° flare (O-ring Face Seal) series that are designed to maximize the leak-free performance and service life of your hydraulic connections. Flaring is a type of forging operation, and is usually a cold working procedure. These are commonly comprised of a hard line that has been flared out to mesh against a fitting and a nut, the flare fitting sits snugly against the fitting and is held tightly in place with the nut. Brass Flare Fittings are of various types.