Abstract: A piercing nut according to the present invention includes an internal thread 11, a ring-shaped punching part 12, a ring-shaped groove 16, and a bearing surface 17. The internal thread 11 is formed at the center of a nut main body 10. The ring-shaped punching part 12 protrudes around the outer periphery of the internal thread 11. The ring-shaped groove 16 is formed around the outer periphery of the ring-shaped punching part 12. The bearing surface 17 protrudes around the outer periphery of the ring-shaped groove 16. The height h of the ring-shaped punching part 12 is equal to or lower than the height H of the bearing surface 17 in the opposite manner to the conventional technique.

Abstract: Provided is a crimp securing structure of a bolt in which a crimp bolt 10 having a crimping recess 13 on the upper surface of the head is crimped onto a metal sheet 30. The thickness of a metal material press-fitted into the crimping recess 13 of the crimp bolt is made smaller at the peripheral edge of the crimping recess 13 and is made larger in the center portion thereof. In order to obtain this crimp securing structure, a crimping die 20 in which a stress-relief recess 23 is formed in a center portion of a convex portion is used to prevent the occurrence of excessive local stress in the crimping recess 13.

Abstract: A piercing nut according to the present invention includes an internal thread 11, a ring-shaped punching part 12, a ring-shaped groove 16, and a bearing surface 17. The internal thread 11 is formed at the center of a nut main body 10. The ring-shaped punching part 12 protrudes around the outer periphery of the internal thread 11. The ring-shaped groove 16 is formed around the outer periphery of the ring-shaped punching part 12. The bearing surface 17 protrudes around the outer periphery of the ring-shaped groove 16. The height h of the ring-shaped punching part 12 is equal to or lower than the height H of the bearing surface 17 in the opposite manner to the conventional technique.

Abstract: Provided are: a sliding plate, the thickness and performance of which can be easily adjusted; and a floor plate for a turnout, using the sliding plate. A sliding plate (3) is provided with a backing material (31) comprising a steel plate or the like, a punching metal (32) disposed on the backing material (31), and a sintered meal powder layer (33) formed on the upper surface (310) of the backing material (31) so as to cover the punching metal (32). The sintered metal powder layer (33) is formed by subjecting an alloy powder for sintering to sintering and rolling, and is impregnated with a lubricating resin through heat melting. The sintered metal powder layer (33) formed on a metal area (321) of the punching metal (32) has undergone high-pressure compression and therefore exhibits a high sintered density and excellent resistance to impact, load and wear.