Dimension standards reflect regional needs:
Flange Width:
US MC-shapes (e.g., MC12×50) have wider flanges (up to 300mm) for heavy loads.
Chinese No. 16 channels (160×65×8.5mm) optimize for narrow flanges in low-rise construction.
Section Modulus:
European UPE channels (e.g., UPE200) have higher section moduli than Asian equivalents, suiting industrial machinery.
Tolerance Requirements:
Japanese standards enforce tighter tolerances (±0.5mm for flange width), while Chinese GB allows ±1mm for mass production.