McMaster 50715K182 37 Degree Flared Fitting for Stainless Steel Tubing 90 Degree Adapter for 1/4" Tube OD x 1/4 NPT Male

Also known as JIC (Joint Industrial Council) fittings, these provide a tight metal-to-metal seal on tubing that is flared to 37°. They withstand high pressure, so they’re often used in hydraulic applications. Made from 316 stainless steel, they resist corrosion from water and chemicals. A complete fitting requires a nut and a sleeve (ferrule) for each tube end. Nuts and sleeves are sold separately.