These adapters are KF-40 to ASA 1 inch vacuum fittings with NO O-Ring groove. They follow ISO-KF standards and have a flange size of NW-40. They are commonly used to make connections between ISO-KF and ASA vacuum fittings. They are often called quick flange fittings because they are quick to assemble. A circumferential clamp and centering ring form the vacuum seal between the connecting flanges. The centering ring contains a rubber elastomer o-ring. The standard sizes for quick flange fittings are KF-10, KF-16, KF-25, KF-40, and KF-50 with flange sizes NW-10, NW-16, NW-25, NW-40, and NW-50, respectively. They are made of corrosive resistant stainless steel.

Adapter KF-40 to ASA 1 inch NO O-Ring Groove 

ISO-KF Flange Size: NW-40 to ASA 1 inch

Common Dimensions: A = 1.65" (42mm), B = 1.49" (38mm), C = 4.2" (108mm)