What is W1 Steel?

W1 steel is a high carbon steelDid you stumble upon a knife made with W1 steel? Or perhaps, you’ve been researching various steels and happened upon the W1 steel. That may have made you wonder if, perhaps, it works for knives.

This guide will give you a comprehensive look on W1 steel, so that all your questions will be answered. We will check out the properties of W1 steel, its advantages and drawbacks, and even its chemical composition. We can then judge if it makes for a good knife blade, or if there are better options out there.

What is W1 Steel?

Cutting hot metal in the smithyW1 steel is a high carbon steel that’s also regarded as a tool steel. That means it’s a good option for manufacturing tools. Part of the appeal of W1 steel is that it’s extremely easy to machine. In fact, no other steel is easier to machine than W1 steel.

More specifically, the W in its designation refers to how it is a “water hardenable” steel. There are several water-hardenable steels that’s part of the group W steels, ranging from W1 to W7 steel. The W1 steel is the most common, as it’s inexpensive and readily available.

Common Uses of W1 Steel

  • Bending Dies
  • Chisels
  • Drift punches
  • Forging dies
  • Heavy forging hammers
  • Knife and Blades
  • Large Blanking tools
  • Lathe centers
  • Milling cutter and boring tools
  • Scissors

W1 Steel Chemical Composition

Blacksmith, metal processing, anvilThis can be a confusing subject, as different online metals authorities can cite different data regarding the chemical composition of W1. One of the problems is that these sources can all be accurate, simply because they’ve been investigating W1 from different sources.

So, you can go with the chemical composition as laid out by materials-today.com, or you may wish to trust the W1 data from Hudson Tool Steel Corporation. Meanwhile, we’re reproducing the chemical composition as described by the AZo Materials online publication for the Materials Science community.

  • Carbon, 0.70% to 1.5%
  • Manganese, 0.1% to 0.4%
  • Silicon, 0.1% to 0.4%
  • Chromium, 0.15%
  • Nickel, 0.2%
  • Molybdenum, 0.1%
  • Tungsten, 0.15%
  • Vanadium, 0.1%
  • Copper, 0.2%
  • Phosphorus, 0.025%
  • Sulfur, 0.025%

Carbon, 0.70% to 1.5%: This is a wide range for carbon content, but it does emphasize the undeniable fact that W1 usually contains a lot of carbon. The carbon is perhaps the most important element for the steel, as it determines its hardness and other resulting characteristics like edge retention and wear resistance. However, the large amount of carbon here can also be blamed for the tendency of W1 to become brittle in certain cases.

If you’re getting the W1 steel in its annealed state so you can do the heat treatment yourself, then it’s crucial that you know the precise carbon content of the W1 steel you’re getting. The amount of carbon will determine how you will do the heat treatment and tempering for the stee.

Manganese, 0.1% to 0.4%: The manganese boosts tensile strength and hardenability, though too much of it leads to reduced ductility. There’s actually not much manganese here, given that some carbon steels contain up to 1.5% manganese. Most steel alloys contain at least 0.3%, because you need a 10-1 ratio of manganese to sulfur to avoid brittleness.

Silicon, 0.1% to 0.4%: Silicon is a deoxidizer, removing oxygen bubbles from molten steel. It also strengthens the steel when it dissolves in the iron. At amounts of more than 0.4% though, it can reduce the machinability of the steel.

Chromium, 0.15%: Chromium is famous for its importance in stainless steel, as it offers corrosion resistance. But stainless steel contains at least 10% or 12% chromium, so the paltry amount here is not for that reason. Instead, it helps with the steel strength a bit.

Nickel, 0.2%: Nickel also helps a bit with corrosion resistance, and it increases the notched toughness and hardenability as well. It also boosts the fracture toughness, at least in low temperatures.

Molybdenum, 0.1%: This improves creep strength, strength in higher temperatures, hardenability, and even the corrosion resistance. But there’s only a little here, as too much can reduce the machinability of the steel.

Tungsten, 0.15%: It helps with the strength and also promotes fine grains.

Vanadium, 0.1%: This is another deoxidizer, and it helps with strength and wear resistance.

Copper, 0.2%: It helps a bit with both corrosion resistance and hardenability.

Phosphorus, 0.025%: It’s normally seen as an “impurity” but in tiny amounts it helps with the machinability and tensile strength. Too much of it leads to brittle steel.

Sulfur, 0.025%: This is another “impurity”, but it also helps with the machinability.

W1 Steel Hardness

It’s not always a clear-cut issue when it’s about the W1 steel hardness, because of the varying carbon content. When you get the steel in its original annealed condition (before heat treatment), its hardness is actually quite low. That’s why it so extremely easy to machine in the first place.

Its hardness as quenched can reach 65 to 67 HRC, but that’s also too brittle. After the tempering, the HRC can get to 56 HRC. But again, this can vary. Even after tempering, the HRC can range from 50 to 64 HRC. Keep in mind that as you get higher up the hardness scale, you also get lower toughness and more brittle steel.

 Properties of W1 Steel

Fantastic Machinability

Making of horseshoe. hot forge used by blacksmithsBasically, it scores a perfect 100% for machinability when you get it in its annealed state. That means you can machine it to the shape you want with no trouble at all, before you do the heat treatment for it.

High Carbon Content

This accounts for the hardness, though at high hardness levels it can be brittle. That’s why the heat treatment brings down the hardness to increase the toughness.

Great Hardenability

It’s easily hardened by heating and quenching in water. It’s like you’re working with plain carbon (or low carbon) steel alloys, but this time you have much higher carbon content.

Low Cost

This is very affordable, and it’s great for high volume manufacturing.

W1 Equivalent Steels or Alternative

Coinage craftsman stamping coins with hammer and anvilThe W1 steel been compared to several other steel alloys. Now we take a closer look as to how they’re similar, and how they’re different.

W1 Steel vs O1 Tool Steel

These are both tool steels, though the O1 is quenched in oil instead of water. The O1 steel can reach good hardness levels that offer high wear resistance, without becoming too brittle.

The W1 steel can be harder, but there’s a greater tendency for brittleness. On the other hand, the W1 steel is much easier to machine, and it costs much less. You go with the W1 when you’re making small parts, and if the working conditions don’t exceed 150 degrees C.

W1 Steel vs W2 Steel

They’re both part of the group W steels. The W1 is more commonly used, simply because it can do a lot of jobs without costing much, plus it’s much easier to machine and form.

But there are some jobs for which the W1 steel may be inadequate, and the W2 may be the better choice. Many say that the W2 is better than W1 for knives, because the W2 contains tungsten and vanadium for greater hardness and a finer structure. The vanadium especially boosts the edge retention.

W1 Steel vs 1095

In many ways, the W1 steel is really similar to 1095 steel. They have similar properties and both are budget options.

It’s just that the 1095 steel is more commonly used for knives because while the W1 steel can be harder, it can get more brittle as well. The 1095 offers better toughness, and it doesn’t need as much meticulous attention during the heat treatment.

Is W1 Steel Good for Knives?

This depends on what you mean by “good”. Technically speaking, it can work for knives. Some budding knifemakers and metalsmiths use W1 steel for practice, because it can be (but not always) easy to work with.

It does have a lot of carbon, but it varies depending on where you get the W1 steel. The characteristics of the steel will also depend greatly on how you treat it. Sometimes you can get very hard steel, but it may be too brittle with not much toughness at all.

In other cases, you can get a much lower hardness rating, although you get good toughness to go with decent edge retention.

That combination of hardness and toughness can work well with a fixed blade. Theoretically, that means it can work as a camping or hunting knife. However, it also comes with very low corrosion resistance. That means you don’t really want to get it wet, and you’d have to oil it constantly to fend off the onset of corrosion.

All in all, the W1 steel can work for a knife. It’s just that there are plenty of better steels out there for the same (or even lower) price. So, you can use W1 steel for your knife blade. There’s really just no really good reason for you to do so.

Pros & Cons of W1 Steel

  • Perfect machinability
  • High carbon content
  • Great hardenability
  • Inexpensive
  • Too much variance in chemical composition (and in carbon content in particular)
  • Hard to balance hardness and toughness


You can find some cheap, no-name knives made with W1 steel. The same goes for other inexpensive cutting tools, like scissors and cutlery. Some manufacturers use it simply because it’s easy to machine, so churning out their products doesn’t entail high costs.

But if you care about the steel in your knife blade (and you probably do, seeing as how you’re doing research on knife blade steels), then W1 is simply not a good option at all. You can find better steels out there that are more useful for knives. You can find more ideal steels that provide good hardness and toughness at the same price as W1 steel.

Frequently Asked Questions

Does W1 steel rust?

The short answer is yes, W1 steel rusts. Actually, it can rust very easily. Its corrosion resistance doesn’t even begin to match the corrosion resistance you get from stainless steel. You’ll need some sort of protective coating on the knife blade for additional corrosion resistance, and then you’ll still end up having to oil the knife blade constantly.

If you’re using cutting tools such as knives and scissors with W1 steel, the best rule is that you shouldn’t get it wet. That’s just asking for trouble. If you do get your knife wet, dry it immediately and apply some oil.

Can W1 tool steel be welded?

Yes, aside from the terrific machinability of W1 steel it can also be welded without any special difficulty. In fact, it can be welded using any of the standard welding methods. The same goes for forming, as it can be formed with conventional forming methods.

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