Coupon tension tests using steel plate specimens with full thickness more than width were conducted to obtain the relation between uniform elongation and rupture elongation. Two types of steel materials (SA440, H-SA700) were selected and three types of coupon tension specimen (JIS No.1A, No.5, and No.12A) were used for the tests. After showing characteristic results of thick specimens, the applicability of a prediction formula for the relation proposed by the authors is investigated. It is clarified that the rupture elongation values obtained from the proposed formula are almost equal to or larger than those of the corresponding test results.
