Which term describes the component known as the 'effective throat' of a fillet weld?

Which term describes the component known as the 'effective throat' of a fillet weld?

• A. The depth
• B. The leg length
• C. The calculated area
• D. The effective throat thickness

Answer: (D)

In fillet welds, the strength comes from the thickness of weld material that actually carries the load—the cross-section that resists shear. The effective throat thickness is that minimum distance from the weld root to the weld face, measured along the cross-section that contributes to strength. This is the dimension used in strength calculations because it reflects the true carrying capability of the weld, not the full leg length along the plates or any penetration depth. The other terms describe different dimensions: depth relates to penetration or overall depth, leg length is the edge-to-edge length along the plates, and calculated area isn’t the standard measure used for fillet weld strength. So the right term is the effective throat thickness.

In fillet welds, the strength comes from the thickness of weld material that actually carries the load—the cross-section that resists shear. The effective throat thickness is that minimum distance from the weld root to the weld face, measured along the cross-section that contributes to strength. This is the dimension used in strength calculations because it reflects the true carrying capability of the weld, not the full leg length along the plates or any penetration depth. The other terms describe different dimensions: depth relates to penetration or overall depth, leg length is the edge-to-edge length along the plates, and calculated area isn’t the standard measure used for fillet weld strength. So the right term is the effective throat thickness.