What are the three primary visual criteria for a sound brazed joint?

• A. Complete wetting, uniform fillet along the joint.
• B. Uniform fillet along the joint and absence of cracks.
• C. Complete wetting, uniform fillet along the joint, and absence of cracks or porosity.
• D. Uniform color and surface roughness.

Answer: (C)

Wetting, fillet, and defect absence are the three visual indicators of a sound brazed joint. Complete wetting means the filler metal spreads fully over and along the joint surfaces, showing the flux and braze alloy have properly reduced oxides and can adhere to the base metals. A uniform fillet along the entire joint indicates consistent capillary flow and filling, meaning the joint is evenly filled without gaps or overly thick sections. The absence of cracks or porosity means there are no internal defects that would weaken the joint or allow leaks. Together, these criteria show the joint was properly brazed, filled, and defect-free. Uniform color or surface roughness aren’t reliable indicators because they can be affected by lighting, oxidation, or surface finishing and do not guarantee proper wetting or defect absence.