To resolve the problem of fluctuations in the dimensions of the expanding process that occurs when the part of the frame sections composing the expanded mesh is more stretched than the other frame sections and the task that the frame sections that are more stretched than the other frame sections and the joint section adjoining these stretched sections are corroded prior to the other sections and thereby shorten the battery life in the manufacturing method of the lead acid storage battery grid using the expanded mesh sheet.

In the angles which are formed between the blade top end face of the protruding blade top end 11 of the dice blade 7c which is used for the expanding process and the sheet metal 4 which is the material to be processed, the angle of the feeding side blade top end face 12 to the sheet metal 4 in the feeding direction is made larger than the angle of the delivered side blade top end face 13.