Three black line diagrams of hook profiles: single radius (high stress), compound radius, and reverse radius (reduced stress), with tensile stress arrows.

“Three side-by-side 2D engineering diagrams of a hook profile, black line art on white background. Left: simple single-radius hook labeled ‘Single radius – high stress concentration’. Center: hook with a compound curve labeled ‘Compound radius’. Right: hook with a subtle reverse radius at the start of the inside curve labeled ‘Reverse radius – reduced stress concentration’. Show arrows indicating tensile stress on the inside surface. Clean technical schematic style, no perspective, no shading, no color.” See more