🔍 Key Concepts

• Butt weld vs fillet weld and how their strengths are usually compared to the plates they join • Typical design assumption for a properly made, full-penetration butt weld • The relationship between weld efficiency and base metal strength in ship construction

💭 Think About

• If a butt weld is made correctly and has full penetration, should it be weaker, equal to, or stronger than the plates it connects? • In ship construction, are butt welds usually designed to be the weak point or at least as strong as the surrounding structure? • Which percentage values look more like typical design efficiencies for partial-strength welds rather than full-strength butt welds?

✅ Before You Answer

• Verify what is meant by a full-penetration butt weld in standard shipbuilding practice • Consider whether a properly executed butt weld is intended to match or exceed the base metal’s strength, not fall far below it • Eliminate choices that would clearly make the joint much weaker than the base metal in a primary hull seam