What is the angle of the shoulder?

What is the angle of the shoulder?

• A. 15 degrees
• B. 45 degrees
• C. 30 degrees
• D. 60 degrees

Answer: (C)

In this context, the shoulder angle is chosen to create a reliable seating surface and easy alignment with the mating part. Thirty degrees hits a practical middle ground: it’s steep enough to guide the part into place and form a solid contact, yet not so steep that it causes binding or excessive stress concentration. A shallower angle around fifteen degrees can leave the seating surface too shallow and prone to gaps or leaks. A steeper angle, like forty-five or sixty degrees, changes the geometry enough to complicate seating, increase debris trapping, and reduce the contact area that bears load or seals. So, thirty degrees provides balanced fit, assembly ease, and sealing performance for typical fittings and shoulders.

In this context, the shoulder angle is chosen to create a reliable seating surface and easy alignment with the mating part. Thirty degrees hits a practical middle ground: it’s steep enough to guide the part into place and form a solid contact, yet not so steep that it causes binding or excessive stress concentration. A shallower angle around fifteen degrees can leave the seating surface too shallow and prone to gaps or leaks. A steeper angle, like forty-five or sixty degrees, changes the geometry enough to complicate seating, increase debris trapping, and reduce the contact area that bears load or seals. So, thirty degrees provides balanced fit, assembly ease, and sealing performance for typical fittings and shoulders.