(57) Abstract Topic Triangle pole form and square cylinder form or cylindrical form salientDue to the time drilling job of the edition roof material compared to, the break uniformlyThe tight frame which the te is broken, does not become cause of the leak in the roofVolt/bolt ahead the sword is offered. Solutions In upper part of screw 3, from major diameter of screw 3Somewhat to the form whose diameter is small, hexagonal cylinder form (the positive hexagonal pilasterCondition is included) sudden facilities to do upper part salient 4, aforementioned upper part salient 4The sword tip 5 which possesses sharp-pointed part 6 in the upper part section sudden facilities was obtained.
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