1. Q: What marking requirements are specified?
A: Each tube bundle or box must be marked with the manufacturer's name or brand, heat number, grade, size, length, specification designation (A268 or A268M), and heat treatment lot.
2. Q: How is the tension test sample oriented for welded tubes?
A: For welded tubes, the transverse tension test specimen is taken perpendicular to the weld. The weld is to be located approximately at the center of the specimen's length.
3. Q: What is the typical delivery condition for these tubes?
A: Tubes are typically supplied in the annealed and descaled condition, cut to random or specific lengths, with ends plain or beveled as ordered.
4. Q: Can tubing be ordered to both A268 and A268M simultaneously?
A: No. The purchase order must specify either A268 or A268M, as they are separate standards with different units. Combining them would cause confusion and non-conformance.
5. Q: When specifying tube dimensions, what is the critical interplay between schedules (SCH) and minimum wall thickness?
A: While schedules (e.g., SCH 40) are commonly used for convenience, the governing requirement in A268/A268M is the minimum wall thickness as calculated from the specified nominal wall, applying the allowable under-tolerance (typically -12.5% for seamless, -10% for welded). The purchased tube must meet or exceed this minimum wall at all points.
