Which statement best describes a scarf joint?

• A. It joins by beveling surfaces on a slope of 1:10 or 1:12
• B. It is a simple butt joint without bevels
• C. It uses a rounded interlock
• D. It is a metal-plate reinforced joint

Answer: (A)

A scarf joint joins two pieces end-to-end by beveling the ends and overlapping them. The bevels create a longer mating surface, which increases glue area and strength, and the slope is typically around 1:10 or 1:12 to balance fabrication ease with structural strength. That’s why describing it as beveling surfaces on a slope of 1:10 or 1:12 matches how scarf joints are formed. A simple butt joint has no bevels and is weaker for long joins. A rounded interlock is not a feature of a scarf joint, which relies on flat, overlapping surfaces. A metal-plate reinforced joint describes a different reinforcement method and isn’t the defining characteristic of a scarf joint.