Using CSA W59, what is the maximum combined warpage for a flange width of 150 mm?

• A. 6 mm
• B. 1.0 mm
• C. 1.5 mm
• D. 2.0 mm

Answer: (C)

CSA W59 establishes distortion limits for welded parts to ensure they will fit and function as intended. One important limit is the combined warpage across a flange, which is tied to the flange width. The idea is that the allowable amount of bend or bow across the width is specified as an absolute value, measured as the maximum deviation from a straight line drawn across the flange.

For a flange width of 150 mm, the standard sets this maximum combined warpage at 1.5 mm. In practical terms, when you place a straightedge across the flange, the furthest point of the warped surface from that straight line should not exceed 1.5 mm anywhere along the width. If the measured distortion is greater, the weld would not meet the specification and would typically require repair or remediation.

The other numbers correspond to different flange widths or are outside the typical tolerance table for this width range, which is why 1.5 mm is the correct limit for a 150 mm flange.