ISO 657-21:1983现行
Hot-rolled steel sections Part 21: T-sections with equal depth and flange width - Dimensions
出版：International Organization for Standardization
专家解读视频
KS D ISO 657-21:2013 - Identical
KS D 3502:2015 - Modified
KS D ISO 657-21:2005 - Identical
JIS G 3192:2005 - Identical
DIN 1024 (1982-03) - Similar
NFA 45 008:1983 - Similar
PN 91/H-93406:1991 - Identical
