Which of the following is an acceptable profile for a fillet weld?

A fillet weld can assume various profiles while still being acceptable based on the standards outlined in the welding code. The profiles include slightly concave, flat-faced, and slightly convex shapes. Each of these profiles can provide adequate strength and fulfill the design requirements.

A slightly concave profile occurs when the weld's surface curves inward slightly. This profile can help distribute stresses more evenly through the weld.

A flat-faced profile means that the weld has a flat surface. This shape is often desirable for aesthetic reasons and can also ensure an even distribution of loads when connecting two surfaces.

A slightly convex profile is characterized by a subtle outward curve at the top of the weld, which can enhance the weld's resistance to cracking and improve overall performance.

Accepting all three profiles acknowledges the variability in welding conditions and the allowable tolerances under the applicable code, thereby accommodating practical considerations encountered in real-world welding applications. Such flexibility ensures that welders can achieve good weld quality under different circumstances while adhering to the requirements of the code.