Daido Tokushuko Kabushiki Kaisha

Honda Giken Kogyo Kabushiki Kaisha

Ntn Corporation

Daido Steel Co., Ltd.

Nagoya Screw Mfg., Co., Ltd.

Nagoyo Screw Mfg. Co., Ltd.

Kunio Namiki

Kazunori Fukizawa

Mitsushi Higuchi

Toshihiko Matsubara

Kenji Takahashi

Tatsumi Urita

Atsuyoshi Kumura

Sukehisa Niwa

Kenji Isokawa

A steel having such a good machinability that it can be directly cut without being annealed and a good induction hardenability. The steel consists essentially of C: 0.37-0.45%, Si: up to 0.35%, Mn: more than 1.0% - up to 1.5%, B: 0.0005-0.0035%, Ti: 0.01-0.05%, Al: 0.01-0.06% and the balance of Fe, the content of N being up to 0.022 and has a fine structure of ferrite crystal grain size number 6 or more as defined by JIS-G0552. In addition to the above basic composition, the alloy may further contain some optional alloying elements. The material is suitable for manufacturing machine structural parts such as drive shafts of automobiles.

Steel for induction hardening

A steel composition for gears, consisting of: 0.10-0.30% by weight of C; less than 0.15% by weight of Si; no more than 1.5% by weight of Mn; no more than 0.015% by weight of P; no more than 0.005% by weight of S; 0.50-1.50% by weight of Cr; 0.005-0.06% by weight of Pb; and the balance being Fe and inevitably included impurities.

Steel for gears, having high strength, toughness and machinability

A high strength bolt made of a steel having a specifically defined chemical composition, i.e., by weight C: 0.30-0.50%; Si: not more than 0.15%; Mn: not more than 0.40%; Cr: 0.30-1.50%; Mo: 0.10-0.70%; and V: 0.15-0.40%, the balance being Fe and inevitable impurities such as P, S, etc. in trace amount. The manufacturing method therefor is featured in a strictly controlled heat treatment in respect to the temperature range such as: hardening by quenching from 940.degree..+-.10.degree. C. and tempering 575.degree..+-.25.degree. C.

Method of manufacturing high strength blank a bolt

High strength bolt

A bolting bar material consists in weight ratio of 0.05.about.0.2% of C, 0.05.about.0.8% of Si, 0.8.about.2% of Mn, not more than 0.035% of P, not more than 0.030% of S, 0.005.about.0.05% of Nb, 0.01.about.0.05% of Al, 0.005.about.0.025% of N, 0.05.about.0.35% in total of at least one element selected from not more than 0.25% of V, not more than 0.25% of Ti and not more than 0.25% of Zr, and if necessary, 0.05.about.1.5% in total of at least one element selected from 0.05.about.0.5% of Ni, 0.05.about.0.5% of Cr and 0.05.about.0.5% of Mo, and the balance of Fe. In the production of the bolting bar material, the steel having the above composition is heated to 1000.degree..about.1100.degree. C., rolled at a finish rolling temperature of 750.degree..about.950.degree. C. and cooled at a rate of 5.degree..about.50.degree. C./sec on average.

Bolting bar material and a method of producing the same

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Nagoya, Japan

Kunio Namiki