On an open root weld on plate, the combined grooved angle of the bevel is?

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

Answer: (B)

The groove angle in a butt weld is determined by how you bevel both edges of the plates and then add those bevel angles together. For an open root weld on plate, a common preparation is to bevel each edge by 15 degrees. when you pair both edges, the two bevels meet to form a combined groove angle of 30 degrees. This provides enough root access for the root weld while keeping the groove size manageable.

If each edge were beveled more (for example, 30 degrees on each side), the combined angle would be 60 degrees, which is not typical for an open root plate weld. If only one edge were beveled (the other kept square), the combined angle would equal that single bevel (15 degrees), which describes a different joint configuration.