Ohtama Co., LTD. – Specializing in permalloy, magnetic shielding, magnetic field measurement, heat treatment and magnetic field cancellation.

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A proven track record and know-how extending back over half a century
Specialist manufacturer of magnetic shields using permalloy

Magnetic field control technologies have become vital in a diverse range of settings, including medical, engineering and various research and development fields.

Ohtama Co., Ltd. has many years of experience in designing and manufacturing magnetic field measurement and magnetic field technologies as a specialist in this field. As a company, we go beyond preconceived ideas in our ongoing quest to tackle issues through creative concepts.

We will continue to respond flexibly and accurately to future magnetic shielding needs through our pioneering


Seven reasons why you should choose Ohtama

1Low cost hydrogen annealing (magnetic annealing)

Every day, we have 8 or more dedicated magnetic annealing furnaces up and running. This enables us to charge only enough space needed for the products in question, meaning we do not bill the customer for the use of a whole furnace. It is our expertise as a manufacturer specializing in hydrogen annealing which allows us to deliver quality products within a short timeframe and at a low cost.

g (magnetic annealing)

2Processing technologies specializing in heat treatment

“How do you minimize deformation caused by warping etc. following heat treatment?” We are heirs to masterful techniques that we keep a closely guarded secret. Only we possess the kinds of proprietary processing technologies which match our customers’ required magnetic characteristics.

Processing technologies specializing in heat treatment

3 Specialist in permalloy, a material that is difficult to process

Permalloy has the unique viscosity of a material rich in nickel. Our seasoned engineers know these properties like the backs of their hands, having devoted themselves to learning the company’s processing techniques, which stem back over half a century of our history as a specialist manufacturer in this field. From the initial cutting of the materials to the final stages, we provide products with a high level of quality based on a system in which our employees learn all of the necessary processes.

 Specialist in permalloy, a material that is difficult to process

4Simulation technologies through the analysis of magnetic fields

We continue to patiently input the results of magnetic field measurements taken over the course of many years into our simulation software as a way to bridge the gap between reality and theoretical values. This enables us to provide analysis of magnetic properties that is by and large accurate at the simulation stage for design plans. From the initial design stage onward, our hope is to continue being the perfect partner for our customers in all matters relating to magnetic fields. 。

5Some of the best technologies for analyzing and measuring magnetic properties in Japan

We use two kinds of ultrahigh performance BH analyzers and HC meters to analyze magnetic permeability and coercive force. We are fully equipped with magnetically Shielded Room for completely isolating facilities from external environments. This is the result of endless consultations concerning measurement methods made together with a range of academic associations and businesses. 。

Some of the best technologies for analyzing and measuring magnetic properties in Japan

6A lineup of some of the finest materials in Japan enabling a quick delivery time

Permalloy is an expensive material that is not so easy to source on the market. The boards come in multiple thickness and widths, and what is more the composition of this material itself is extremely varied. In order to deliver permalloy, which can take anything from 4 to 6 months to obtain, to our customers in a short space of time, we maintain a large stock of dozens of varieties of this material. We are the only company in Japan with the capability to assemble the kind of stock which enables us to meet the customer’s needs at any given moment.

A lineup of some of the finest materials in Japan enabling a quick delivery time

7Ohtama spirit

7. Ohtama has established a business framework based on its founding spirit of “Aim high and remain humble,” under which we strive to avoid arrogance and remain humble despite our current standing as Japan’s leader in magnetic shield products. We manufacture and develop products in pursuit of the truth without losing our zeal for technology. In both times of hardship and success, it is this company culture which never fails to unite our employees. We believe the Ohtama spirit is the reason why we continue to find favor among our customers.

Ohtama spirit


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