Patent ID: 9534282
Date: 2017-01-03
CPC Classifications: B21H,B21K,B23G,C22F,F16B

Claim:
1. An aluminum alloy bolt made of an aluminum based alloy of 6000 series, having a shaft with a threaded portion, wherein the shaft has a tensile strength being equal to or more than 500 MPa and has a hardness distribution such that the hardness steeply rises from approximately 130 Hv at a surface to the order of approximately 170 Hv in the span from 0 to a distance of 0.5 mm from the surface, and then gradually rises from approximately 170 Hv to the order of approximately 180 Hv until reaching a center position of the shaft, and a hardness of the thread portion has a hardness distribution such that the hardness is on the order of 160 Hv at a depth of 0.1 mm.