Which statement is true regarding minimum allowable bend radii for 1.5 inches OD or less aluminum alloy and steel tubing of the same size?

Which statement is true regarding minimum allowable bend radii for 1.5 inches OD or less aluminum alloy and steel tubing of the same size?

• A. The minimum radius for steel is greater than for aluminum
• B. The minimum radius is the same for both materials
• C. The minimum radius for aluminum is greater than for steel
• D. Cannot determine

Answer: (A)

Bend radius depends on how much the material can deform without cracking or wrinkling. Aluminum alloys used for tubing are typically quite ductile and can tolerate tighter bends, while steel of the same size often has higher strength and less elongation before failure. Because the outer fibers must stretch during bending, steel is more prone to cracking if the bend is too sharp, so a larger bend radius is required to avoid damage. Therefore, for the same 1.5 inches OD or smaller tubing, the minimum bend radius is greater for steel than for aluminum. The exact numbers vary with wall thickness and alloy, but the general trend holds: steel needs a larger radius to bend safely.

Bend radius depends on how much the material can deform without cracking or wrinkling. Aluminum alloys used for tubing are typically quite ductile and can tolerate tighter bends, while steel of the same size often has higher strength and less elongation before failure. Because the outer fibers must stretch during bending, steel is more prone to cracking if the bend is too sharp, so a larger bend radius is required to avoid damage. Therefore, for the same 1.5 inches OD or smaller tubing, the minimum bend radius is greater for steel than for aluminum. The exact numbers vary with wall thickness and alloy, but the general trend holds: steel needs a larger radius to bend safely.