The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 19, 2019
Filed:
Mar. 25, 2015
Bridgestone Corporation, Tokyo, JP;
Takayuki Saito, Tokyo, JP;
BRIDGESTONE CORPORATION, Tokyo, JP;
Abstract
Provided are a metal wire rod drawing die that has a longer life than conventional dies and that can prevent damage to a metal wire rod surface and a method for manufacturing the die. In a metal wire rod drawing die (), a die hole () for inserting a metal wire rod is formed. Where Rarepresents a surface roughness of an inner surface of the die hole from a bearing section () to an approach section () corresponding to an area reduction rate of 30% in an axial direction of the die hole, Rarepresents a surface roughness of the inner surface of the die hole from the bearing section to the approach section corresponding to the area reduction rate of 30% in a direction orthogonal to the axial direction of the die hole, and Rarepresents a surface roughness of an inner surface of the bearing section of the die hole in the axial direction of the die hole, the Ra, the Ra, and the Rasatisfy a relationship represented by 0.14 μm>Ra>Ra>Ra