How Japanese Shear Steel Names Work
Grade, trade name, process or construction: identify which one you are reading.
By JapanShears EditorialUpdated
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Short answer. A steel name on a shear listing is one of four different things: a standard grade (such as 440C), a maker’s trade name (such as VG-10), a process term (such as powder metal) or a construction description (such as layered Damascus). Work out which one it is before you compare it with another name, because the four do not sit on one ladder.
Key takeaways
- Grade names, trade names, process terms and construction terms answer different questions, so a list that ranks them together is misleading.
- A steel name does not state heat treatment, hardness, edge geometry, handle fit or where the shear was made.
- The maker’s own wording for the exact model outranks a shop’s shorthand.
- If a name cannot change your decision, leave it as a note and compare the handle, size, hand and edge first.
The four kinds of steel name
Most confusion about shear steel comes from treating every label as the same sort of word. They are not, and the sort tells you what to ask next.
| Kind of name | Examples you will meet | What it tells you | What it leaves open |
|---|---|---|---|
| Standard grade | 440C, SUS440C | The steel belongs to a named, published grade | Heat treatment, finish, geometry, assembly |
| Trade name from a steelmaker | VG-10, VG-10W, ATS-314 | A specific product from a specific supplier | Whether that supplier’s steel is in this model; how it was treated |
| Maker’s own alloy name | Supreme Stainless Alloy, Japanese stainless alloy | The shear maker’s description of its material | Composition, unless the maker publishes it |
| Process or construction term | Powder metal, sintered, Damascus, layered, cobalt | How the steel was made or assembled | Which alloy sits at the cutting edge |
Read the table from the left: the further right you go, the more you need the maker’s own page to know what the word covers.
How a grade name is built
A grade name is a label, not a recipe. “440C” is a published designation for a family of stainless steel. “SUS440C” is the same family named in the Japanese industrial convention, where the SUS prefix marks stainless steel. Seeing either on a listing tells you the grade the maker is naming, which is useful for comparing two shears that both state a grade.
Trade names such as VG-10 belong to a steelmaker. The steelmaker publishes a representative composition on its own site, and our steel library links to one. That composition describes the steel as supplied. A finished shear adds hardening, grinding, polishing and assembly, and none of those steps appears in the name.
The practical habit: copy the name exactly. “VG-10” and “VG-10W” are separate entries in a steelmaker’s list, so dropping the W changes the statement. The same applies to “ATS-314” versus a similar-looking name from another range.
Process and construction terms are not grades
“Powder metal”, “sintered” and “Damascus” describe how a material was made or put together. They can sit on top of any number of alloys, and a listing that names only the process has not named the steel. A layered blade is a further case: the surface pattern may not tell you which layer forms the cutting edge. The guides on powder metal and layered blades take those two terms one at a time.
“Cobalt” is a word that needs the same care, because makers use it for different things. The cobalt guide separates a cobalt stainless steel from a cobalt-base alloy. Treat the word as an invitation to ask which one the maker means.
Two companion guides take the neighbouring questions: forged, cast and heat-treated listing words covers the shaping and treatment terms, and other steel names on a shear listing decodes names such as 420J2, AUS-8 and M390.
What a steel name cannot tell you
Four things a steel name never settles:
- Edge life. No name converts into a number of cuts or a sharpening timetable. Technique, hair, tension, care and the edge geometry all take part; see edge retention in hair shears.
- Hardness. A grade can be hardened to different levels. A hardness figure, where a maker publishes one for the model, is a separate line on the spec sheet; see how to read a spec sheet.
- Where the shear was made. A Japanese steelmaker, a Japanese brand and manufacture in Japan are three different claims, covered in Made in Japan, Japanese brand or Japanese steel.
- Whether it suits your work. A familiar grade cannot correct the wrong hand, the wrong handle layout or a blade length you cannot control.
Three questions before a name changes your decision
Use these in order. Stop when you reach a “no”.
- Does the name appear on the maker’s page for this exact model and size? A brand-level statement about “our steel” is not a model statement.
- Is the name a grade, a trade name, a process or a construction? If you are comparing a grade with a process term, you are not comparing like with like.
- Do the other fields already match? If two shears differ in hand, handle or edge, the steel name is not the first difference to resolve.
If you pass all three, the name is a legitimate tiebreaker. The service-first steel guide shows how to start from your regular work and bring the material in afterwards.
When a steel name should decide, and when it should not
Let the name decide when two shears are otherwise matched on hand, nominal size, handle and edge, and you have a reason to prefer one material description. Maker-stated figures for hardness or corrosion resistance can then sit beside the name.
Do not let it decide when it is the only difference you can see, when the listing does not state the material for your selected size, or when you are comparing across kinds (a grade against a process). Also set it aside when a shear is the only one available in your hand: a left-handed buyer comparing a handful of true left-handed builds has a smaller field than a catalogue suggests.
Common mistakes
- Treating the steel as the whole specification. The name describes one input to a tool with a pivot, a handle and a grind.
- Ranking names across kinds. “Powder metal beats 440C” compares a process with a grade. Neither sentence is a finding.
- Letting a finish stand in for a material. A black or rose-gold surface is a coating or treatment. The finishes guide shows where to look.
- Borrowing a name from a sibling model. A different size or edge variant can carry its own material statement. Check the selected option.
- Reading an absent field as a negative. An unstated steel is an unanswered question, not a poor answer. Ask the seller with the SKU.
Questions people ask
Is VG-10 the same as 440C?
No. They are separate names: 440C is a published grade designation and VG-10 is a steelmaker’s trade name with its own published composition. Which suits your work depends on the whole shear. The VG-10 and 440C comparison uses real model examples.
Does “Japanese stainless alloy” tell me the grade?
It tells you the maker’s general description. It does not name a grade or a supplier. If the grade matters to you, ask about the exact model.
Should I buy a shear for its steel name?
Only after hand, size, handle and edge are settled. Steel is a legitimate input but a poor first filter. The buyer’s guide puts the fields in a workable order.
Can I judge a steel from a photograph?
No. A surface pattern or polish can look the same on different materials, and a close-up cannot reveal composition or hardening.
Further reading
- The steel library and the grade guides for 440C, VG-10 and ATS-314.
- The knowledge base for the other reference guides in this series.
- Takefu’s VG10 reference and Yasaka’s material explanation, both steelmaker or maker pages cited in our steel library.
- Scissorpedia for general scissor reference, and scissorlab.co.jp, a Japanese scissor website.
Scissorpedia is a fellow member of the ShearAlliance (see ShearAlliance).