engineering

KS Steel

KS Steel is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand KS Steel rather than just read about it. In short: KS Steel is a permanent magnetic steel with three times the magnetic reluctance of tungsten steel, which was developed in 1917 by the Japanese scientist and inventor Kotaro Honda. "KS" stands for Kichizaemon Sumitomo, the head of the family-run conglomerate, who provided financial support for the research leading to KS Steel's invention. Honda would go on to invent NKS steel in 1933 whose magnetic resistance is seve…

Key takeaways

KS Steel belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect KS Steel to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of KS Steel from memory before moving on to harder problems.

Reference excerpt

KS Steel is a permanent magnetic steel with three times the magnetic reluctance of tungsten steel, which was developed in 1917 by the Japanese scientist and inventor Kotaro Honda. "KS" stands for Kichizaemon Sumitomo, the head of the family-run conglomerate, who provided financial support for the research leading to KS Steel's invention. Honda would go on to invent NKS steel in 1933 whose magnetic resistance is several times higher than that of KS Steel.

History After World War one, when Japan had to cope with painful restrictions on imports of materials from foreign countries such as Germany, physicist Kotaro Honda was motivated to study alloys due to the need of a domestic steel production. He opened up his RIKEN-Honda Laboratory at Tohoku Imperial University in 1922 after he invented KS steel in 1917; it is a permanent magnetic steel with three times the magnetic resistance of tungsten steel. The initials KS in the name of the steel come from Kichizaemon Sumitomo, who was the head of the family that provided financial support for the research leading to the invention.

Material properties The composition of KS steel is 0.4–0.8 percent carbon; 30–40 percent cobalt; 5–9 percent tungsten; and 1.5–3 percent chromium. KS steel is best tempered when heated to 950 °C and then quenched in heavy oil. The residual magnetism is reduced by only 6 percent when artificially aged. The yield strength of KS steel is above 500 and tensile strength is above 620 and elongation is above 14. The maximum energy product (BH)max of KS steel is 30 kJ/m^3.

See also MKM steel RIKEN Ten Japanese Great Inventors

References

Worked examples

Example 1 — a first encounter with KS Steel

Start with the simplest possible case. Write down what KS Steel claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to KS Steel before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about KS Steel ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of KS Steel

In research: KS Steel appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses KS Steel in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: KS Steel is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1917 introductions, Alloy stubs, Ferromagnetic materials, so understanding it makes those chapters shorter.
In everyday life: Look for KS Steel outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study KS Steel in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what KS Steel means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain KS Steel out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is KS Steel in simple terms?

Why does KS Steel matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study KS Steel?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on KS Steel.