A scratch or nick in aluminum tubing can be repaired provided it does not

A scratch or nick in aluminum tubing can be repaired provided it does not

• A. appear in the heel of a bend
• B. appear on the inside of a bend
• C. exceed 10% of the tube OD on a straight section
• D. occur at the end of the tube

Answer: (A)

When assessing scratches or nicks on aluminum tubing, location matters as much as size. The bend area, especially the heel where the straight section begins to curve, is a high-stress region. The metal is subjected to unusual bending stresses there, and a defect in that zone can act as a crack initiation point that will grow under service loads. Because repairs in that critical bend area are unreliable and could compromise structural integrity, a scratch or nick cannot be repaired if it appears in the heel of a bend. If the damage is elsewhere, it may be repaired or the tube replaced according to approved procedures.

When assessing scratches or nicks on aluminum tubing, location matters as much as size. The bend area, especially the heel where the straight section begins to curve, is a high-stress region. The metal is subjected to unusual bending stresses there, and a defect in that zone can act as a crack initiation point that will grow under service loads.

Because repairs in that critical bend area are unreliable and could compromise structural integrity, a scratch or nick cannot be repaired if it appears in the heel of a bend. If the damage is elsewhere, it may be repaired or the tube replaced according to approved procedures.