We provide custom products that fully cater to customers' requests.

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.

Our strengths in special steel materials

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.

Testing / Inspection system

We were the first special steel manufacturer in Japan to receive ISO/TS16949 certification (which is superseded by IATF) to manufacture soft-magnetic stainless steel for automobiles (cold drawn bars and drawn wires) and heat-resistant steel for automobiles (cold drawn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.

Product Information

Special steel materials


Steel type


Examples of product usage


Heat-resistant steel

SUH11, SUH3, and others
SUH35, 21-2N, and others
<Alloy type>

We have the top share in Japan for engine valve heat-resistant steel. We manufacture various types of heat-resistant steels.

Intake valve
Exhaust valve

Stainless steel

and others

Special stainless steel that has the requested characteristics (heat resistance, corrosion resistance, high strength, etc.)

EGR valve

Magnetic materials


Steel type


Examples of product usage


Electromagnetic stainless steel

and others

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.

Injector parts
General soft-magnetic valve parts
Magnetometric sensor parts

Non-Pb TICS free-cutting soft-magnetic stainless steel

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.

Injector parts
General soft-magnetic valve parts
Magnetometric sensor parts

High-hardness, soft-magnetic stainless steel


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.

Injector parts
General soft-magnetic valve parts

Flux density soft-magnetic material

ME1F (Free-cutting pure iron)
MES2CS (2.2% silicon TICS free-cutting steel)
MES3F (3% silicon free-cutting steel)
K-MP11E (Permendur)

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.

Relay parts

Soft-magnetic cores

Motor parts

Sensor parts


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.

Sensor cores
Magnetic shields



Steel type


Examples of product usage


Low thermal expansion alloy

K-EL70 (Invar)
K-EL50 (Super invar)
K-ET52 (Kovar)

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.

Optical communication parts
Aligner parts
Precision measurement equipment
Precision processing machinery
Semiconductor production line

Free-cutting Invar / Kovar


Our newly invented TICS realizes free-cutting of difficult-to-cut Fe-Ni alloys.

Optical communication parts
Aligner parts

Contact Us

Tohoku Steel Co., Ltd.
23 Nishigaoka, Murata, Murata-machi, Shibata-gun, Miyagi,
989-1393 Japan

On special steel materials and precision processing products (Please inquire to our office nearest your area.)

Contact Phone FAX
Tokyo Office +81-3-3270-1851 +81-3-5255-6775
Nagoya Office +81-52-269-3626 +81-52-269-3632
Sendai Office +81-22-248-3151 +81-22-304-1021

On heat treatment

Contact Phone FAX
Heat treatment plant +81-224-83-5606 +81-224-82-1023

Special alloys / Industrial instrumentation

Contact Phone FAX
Research & Development Department
Development Sales Team
+81-224-51-8223 +81-224-82-1021

Company Information / Recruitment / IR, etc.

Contact Phone FAX
General Affairs Team, Operations Department +81-224-82-1010 +81-224-82-1020