| 摘要 |
PROBLEM TO BE SOLVED: To provide a common screw to reliably prevent erroneous insertion of a cross driver and prevent breakage of a screw head. SOLUTION: A drive socket comprises an axially extending division groove formed in a screw head in a manner to have depth; a first short recessed part 14a, stretched along the long axis of the division groove, formed in the bottom wall of the division groove; and a second short recessed part 14b stretched along an axis N vertical to the long axis L of the division groove 15. The first and second short recessed parts 14a and 14b are provided with four terminals 14c in collaboration, and a cross-shaped recessed part to support the cross type driver is demarcated. A rectangular recessed part 12 for a rectangular socket type driver is formed in a section demarcated by four terminals 14c of the first and second short recessed parts 14a ands 14b. A point of intersection between diagonal lines of the rectangular recessed part 12 is identical with a point of intersection between the long axis L and the axis N vertical to the long axis L. The angle of one diagonal line 13b of the rectangular recessed part 12 with the axis N vertical to the long axis L forms an angleαnot equal to 45 deg..
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