When is no length dimension necessary for a fillet weld?

• A. When there is no length specified elsewhere
• B. When the joint is a spot weld
• C. When the fillet weld is to be the full length of the joint.
• D. When the weld is decorative

Answer: (C)

When a fillet weld runs the full length of the joint, you don’t need a separate length dimension because the weld length is already defined by the joint length shown on the drawing. The joint length serves as the weld’s length, so you only specify the leg sizes and throat depth for the fillet. If the weld does not cover the entire joint, then a separate length dimension (or multiple lengths) would be needed to describe how long each weld segment should be.

Other scenarios don’t apply here: if there’s no length specified elsewhere, you’d still need to know the joint length or another way to define the weld length to avoid ambiguity; spot welds and decorative welds aren’t governed by the rule about full-length continuity—the key idea is whether the weld spans the whole joint, in which case no extra length dimension is required.