The arc along a board's length is called which term?

The arc along a board's length is called which term?

• A. Crown
• B. Curl
• C. Twist
• D. Kink

Answer: (A)

Crown refers to a board’s slight arch along its length. When you inspect a piece of lumber, the center line often sits higher than the edges, creating a gentle curve from end to end. That highest point is the crown. This warp matters in planning and assembly because it can affect how flat a surface will be and how tightly joints come together; you might plane to reduce crown or orient boards so the crown works with the intended layout. The other terms describe different distortion types: curl involves bending or curling along the surface or edges, twist is when the ends are rotated out of plane along the length, and kink is a sharp bend in a short section. Since the question focuses on the arc along the length, crown is the best fit.

Crown refers to a board’s slight arch along its length. When you inspect a piece of lumber, the center line often sits higher than the edges, creating a gentle curve from end to end. That highest point is the crown. This warp matters in planning and assembly because it can affect how flat a surface will be and how tightly joints come together; you might plane to reduce crown or orient boards so the crown works with the intended layout. The other terms describe different distortion types: curl involves bending or curling along the surface or edges, twist is when the ends are rotated out of plane along the length, and kink is a sharp bend in a short section. Since the question focuses on the arc along the length, crown is the best fit.