Special Steels and Magnetic materials

Our special steel materials are manufactured to be completely customized. We select the dimensions, surface roughness, and other characteristics in accordance with customers' requests.
In addition, based on the knowhow we have accumulated through our experience, we can propose solutions to your issues that use new types of steels or treatment methods.

We hold the top share in Japan for engine valve heat-resistant steel and soft-magnetic stainless steel. We also sell our steel widely overseas. In particular, in 1960 Tohoku Steel became the first company in the world to develop soft-magnetic stainless steel. We carry a wide lineup for various usages to meet customer needs. We promote labor-saving automated operation for delivery and production at our plants in order to achieve shorter delivery times and appropriate costs.

We were the first special steel manufacturer in Japan to receive ISO/TS16949 certification (which is superseded by IATF) to manufacture soft-magnetic stainless steel for automobiles (cold drawn bars and drawn wires) and heat-resistant steel for automobiles (cold drawn bars and drawn bars). In this way, we maintain a quality assurance system that gives our customers a sense of security.
To test and inspect steel materials, we use strictly calibrated testing and inspection equipment in order to confirm that product characteristics (e.g., hardness, tension, and magnetic properties) meet customers' requests.
We use eddy current and ultrasonic testing methods to inspect 100% of many of our products so as to ensure the soundness of both their surfaces and internal components.
Classification |
Steel type |
Features |
Examples of product usage |
Usage |
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<Martensite-based> |
We have the top share in Japan for engine valve heat-resistant steel. We manufacture various types of heat-resistant steels. |
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Intake valve |
Stainless steel |
SUS310S, |
Special stainless steel that has the requested characteristics (heat resistance, corrosion resistance, high strength, etc.) |
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EGR valve |
Classification |
Steel type |
Features |
Examples of product usage |
Usage |
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K-M31, |
Since the 1960 launch of K-M31, the world's first soft-magnetic stainless steel, we have maintained the No. 1 share in Japan. We have a wide lineup to meet various needs. |
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Injector parts |
K-M38CS, etc. |
Quite different from Pb free-cutting and MnS free-cutting steels. A completely new type of free-cutting steel: TICS It received the 21st Century Invention Award. |
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Injector parts |
K-M57 |
Soft-magnetic stainless steel is commonly understood to be a mechanically soft material. Defying such a conception, this is a precipitation-hardened ferrite-based soft-magnetic stainless steel that we were the first in the world to mass produce. |
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Injector parts |
ME1F (Free-cutting pure iron) |
We provide pure iron and silicon iron free-cutting steels with superior magnetic properties. We have distinct pure iron-based magnetic materials, such as highly saturated magnetic flux density materials and highly permeable magnetic materials. |
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Relay parts Soft-magnetic cores Motor parts Sensor parts |
Permalloy |
K-MH60(PB), K-MH50(PC), and others |
Alloys made mainly of iron and nickel with the best soft magnetism. They are essential materials in the electronics field; applications include magnetic heads, iron cores, shields, sensors, and more. |
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Armature |
Classification |
Steel type |
Features |
Examples of product usage |
Usage |
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K-EL70 (Invar) |
Iron-nickel alloys containing around 36% nickel provide an extremely small thermal expansion coefficient at near room temperature due to magnetic transformation. They are an essential material for precision measurement equipment, precision machine parts, and so forth. Kovar's thermal expansion coefficient is adjusted to be equivalent to that of ceramics, and it is used for sealing. |
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Optical communication parts |
K-EL70CS |
Our newly invented TICS realizes free-cutting of difficult-to-cut Fe-Ni alloys. |
Optical communication parts |
Tohoku Steel Co., Ltd.
23 Nishigaoka, Murata, Murata-machi, Shibata-gun, Miyagi,
989-1393 Japan
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