What is the main difference between AN fittings and MS fittings?

What is the main difference between AN fittings and MS fittings?

• A. the manner in which the hydraulic tube fits to the fitting
• B. the size of the hydraulic tube
• C. the material of the tube
• D. the color of the fitting

Answer: (A)

The key idea is how the tube ends attach and seal to the fitting. AN fittings use a flared tube end that seats against a conical sealing surface inside the fitting; when you tighten the nut, the flare is pressed into that seat to form the seal. MS fittings don’t rely on a flare for the seal—they use a different arrangement, typically a compression ferrule or sleeve that clamps the tube into a seating surface inside the fitting, creating the seal without a flare. So, the main difference is the method the tube uses to fit into and seal with the fitting. This also means the prep and tooling are different: flaring for AN versus ferrule/compression for MS.

The key idea is how the tube ends attach and seal to the fitting. AN fittings use a flared tube end that seats against a conical sealing surface inside the fitting; when you tighten the nut, the flare is pressed into that seat to form the seal. MS fittings don’t rely on a flare for the seal—they use a different arrangement, typically a compression ferrule or sleeve that clamps the tube into a seating surface inside the fitting, creating the seal without a flare. So, the main difference is the method the tube uses to fit into and seal with the fitting. This also means the prep and tooling are different: flaring for AN versus ferrule/compression for MS.