Ykk Corporation

Takuya Koizumi

Atsushi Ogihara

Takahiro Fukuyama

Yasuharu Yoshimura

Kouta Kido

Itaru Hasegawa

Kazuya Akitsu

Chikako Hiromi

Koichi Mikado

Yoshio Taira

Takanori Kumei

Jun Kiyohara

Kousuke Seki

Kouichi Mikado

Yasuhara Yoshimura

Kyudo Ota

Yuri Katsumi

A copper alloy for fastening wherein the alloy has a structure of a mixture of &#x3b1;-phase and a &#x3b2;-phase; and wherein the alloy has a composition represented by the general formula: CuZnMn, where bal., a, and b are expressed in % by mass, bal. represents the balance, 34&#x2264;a&#x2264;40.5, 0.1&#x2264;b&#x2264;6, and inevitable impurities may be contained; and the composition satisfying the equation (1): b&#x2265;(&#x2212;8a+300)/7, where 34&#x2264;a&#x3c;37.5 and equation (2): b&#x2264;(&#x2212;5.5a+225.25)/5, where 35.5&#x2264;a&#x2264;40.5.

Fastening copper alloy

An improved season cracking resistance of a metallic fastener member is provided and includes a copper alloy containing zinc as a base material. The metallic fastener member includes, as a base material, a copper alloy containing zinc, and the metallic fastener member has a surface to which a rust prevention treatment has been applied and has such a property that, when analyzed by a scanning X-ray photoelectron spectroscopy apparatus, a maximum value of an atomic concentration of Mn is detected at a depth of 100 nm or less from the surface.

Metallic fastener member and fastener equipped with same

A metallic fastener member has a specific color of light gold and also has high strength, discoloration resistance and high workability to withstand practical use. A metallic fastener member including a base material of a copper alloy having composition containing 1 to 30% by mass of Zn and 1 to 11% by mass of Ni, the balance being Cu and inevitable impurities, wherein the metallic fastener member has a Vickers hardness of Hv 120 or more and less than Hv 220.

Metallic fastener member having light gold color, and fastener provided therewith

A copper-zinc alloy product of the invention contains zinc in an amount of higher than 35% by weight and 43% by weight or less and has a two-phase structure of an &#x3b1;-phase and a &#x3b2;-phase. Further, the ratio of the &#x3b2;-phase in the copper-zinc alloy is controlled to be higher than 10% and less than 40% and the crystal grains of the &#x3b1;-phase and the &#x3b2;-phase are crushed into a flat shape and arranged in a layer shape through cold working. According to the copper-zinc alloy product, it is possible to decrease the copper content and to appropriately secure the strength and cold workability by appropriately controlling the ratio of the &#x3b2;-phase.

Copper-zinc alloy product and process for producing copper-zinc alloy product

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Toyama, Japan

Takuya Koizumi