| 摘要 |
A welded portion (1) formed at a joint between a plurality of steel plates (10) is formed of a plurality of nuggets (11) arranged along a virtual closed curve (12), and when the thickness of the thinnest steel plate (10) of the steel plates (10) is denoted by t, the diameter d of each nugget (11) is 3 √t or less, and the pitch p between adjacent nuggets is 2 d or more but no more than 5 d, and the number of nuggets is three or more. |
