Patent ID: 9212682
Filing Date: 2015-12-15
Classification: B23K,F16B

Abstract:
1. A fastening member which is one of a bolt, a nut or a washer employed for fastening a body being fastened by a screw tightening action, the fastening member having a tapered-ring-body-shaped part, which is formed into a ring body shape with a gradually increasing diameter toward a seating surface formed into a circular-planar-band-ring-shape concentric with an axis so as to press against the body being fastened, wherein the taper angle of the tapered-ring-body-shaped part is an acute angle, and an upright surface is formed in an outer circumferential surface of the tapered-ring-body-shape part and vertically erected from the body being fastened, so that an outer diameter of the circular-planar-band-ring-shaped seating surface has a size in a range for creating a surface pressure from the seating surface so as to effectively press against the body being fastened, an inner circumferential surface of the tapered-ring-body-shaped part includes a concave-curved surface.