Have you stumbled upon a knife made with M2 steel? It’s probably a Benchmade knife, since the brand used the M2 tool steel extensively back in the old days. A good example of their knives is the 710HS McHenry & Williams M2 Plain Edge Knife, which was the first knife to carry the Axis mechanism.
But the 710HS McHenry & Williams M2 Plain Edge Knife in M2 steel is now discontinued, and the M2 is quite rare nowadays. It’s mainly because manufacturers find the M2 a lot more difficult to work with, unlike many of the modern steels.
This manufacturing and production difficulty will just add to the price, and consumers won’t pay the high prices considering they can find better steels with superior features at lower prices.
Still, if you want the M2 for nostalgic reasons, you can always go for one. Or, you can try working with it if you’re a budding metalsmith. It’s challenging to work with, but you can sure improve your techniques while trying the M2 steel out.
What is M2 tool steel?
The M2 steel is a high-speed tool steel. It’s the kind of tool steel that retains a lot of its hardness and toughness at red heat. That means when you have a tool made with this steel, the tool can cut at high speeds even if it becomes red-hot due to friction.
Nowadays, it’s more known as the high-speed steel that’s replacing the formerly popular T1 steel. That’s because the M2 is a lot better in terms of bending strength, thermo-plasticity, and toughness.
There used to be quite a few M2 steel knives around, mainly from Benchmade. Even Gerber made a few cutlery pieces from M2. But today, you don’t normally find it in handheld knives at all.
Common Uses of M2 steel
Here are some of the more common uses of M2 steel:
- Milling cutters
- Rolling racks
- Thread-roll dies
- Reamers
- Drills
- Saws
- Knives (back in the old days)
M2 Steel Chemical Composition
These are the significant elements in the M2 formula:
- Carbon, 0.85%
- Molybdenum, 5%
- Chromium, 4.1%
- Vanadium, 1.8%
Carbon, 0.85%: The M2 has a notably high amount of carbon, as it determines the hardness, strength, and hardenability of the steel. With this amount of carbon, you get a lot of hardness that leads to good edge retention and wear resistance.
Molybdenum, 5%: It works with the vanadium as a carbide former, and the carbides lead to high wear resistance. When combined with the tungsten and the chromium, it forms the high-speed steel that makes the M2 so widely used for industrial applications. You don’t get the high-speed tool steel you want without this much molybdenum.
Molybdenum increases hardenability and the steel’s strength even in extremely high temperatures. It also helps with creep strength, and with corrosion resistance too.
Chromium, 4.1%: The chromium here isn’t really for corrosion resistance, since you need at least 10% or even 12% to qualify as stainless steel. But here, it’s used to boost the hardenability of the steel and also to increase its yield strength.
Vanadium, 1.8%: Again, it’s here because it helps with the hardenability of the M2 steel. It also boosts the shock loading resistance and fracture toughness.
Tungsten, 6.4%. The tungsten combines with the molybdenum, chromium, and vanadium to give you the high-speed tool steel. Because of the tungsten, the M2 is able to retain its hardness even when it’s working in extremely high temperatures.
M2 Steel Hardness
The hardness of the M2 steel is quite notable, since it can reach as high as 62 HRC. That’s very hard, and very few steels can match that level. It’s the main reason why you’d want the M2 steel in a knife in the first place.
Because of this hardness, its edge retention is quite good. Having a knife with M2 for the blade means you won’t have to sharpen the blade too frequently.
Does M2 steel rust?
Yes, and very easily too. It’s not a type of stainless steel, not with its 4% chromium. You need at least 10% or 12% chromium to qualify.
What that means is that you will need to oil your M2 steel knife regularly. Try not to get it wet, and dry it as quickly as you can when you do get it wet. This M2 simply rusts too easily.
Properties of M2 steel
These are the properties you can expect from M2 steel:
Effective Even at High Temperatures
This is perhaps its most important feature, which is why it has become so popular in various industrial applications. You can use the steel for cutting at high speeds (such as for industrial saws and cutters) because the heat produced by the friction won’t bother its effectiveness.
Good Edge Retention
The M2 maintains a sharp edge very well, although when it becomes dull it can be a problem to sharpen.
Great Wear Resistance
This is another benefit of the high hardness you get from M2. The blade won’t wear out too easily, especially as you won’t have to sharpen the blade that often.
Decent Toughness
Hard steels are often lacking when it comes to toughness, but the M2 toughness is actually quite good. It won’t chip off too easily, unlike other steels that are as hard as the M2.
Low Corrosion Resistance
You will need to keep your M2 steel knife oiled.
M2 Equivalent Steels or Alternative
Let’s compare the M2 steel with other tool steels that you may encounter.
M2 steel vs A2
Unlike the M2, the A2 is still found in quite a few knives these days, especially in fixed blades. It offers decent edge retention, though it won’t match the edge retention of the M2. The toughness is excellent for the A2, and it’s better than the M2.
The A2 is somewhat difficult to sharpen, but then the M2 is worse. At least the A2 offers some decent corrosion-resistance, unlike the M2.
M2 steel vs D2
When it comes to tool steels used for knives, the D2 is perhaps the most popular. It’s been used in knives since WWII, and it’s still popular today. The D2 offers good edge retention, though the M2 is better at this. The D2 is also hard to sharpen like the M2, and they both offer good toughness.
The D2 corrosion resistance is low, but then again, the M2 is much lower. All in all, you’re better off with the D2, and it’s even more affordable as well.
M2 steel vs H13
The H13 is another tool steel, also renowned for its high strength and toughness, great hardenability, and red-hot hardness. It’s very popular for use in hot working dies. Its hardness doesn’t really compare to the M2 steel, especially if used in knives. You go with the M2 if you want high hardness, but you go with H13 if you want high toughness levels.
Is M2 Steel Good for Knives?
This really depends on your perspective. Let’s say you get an M2 steel knife as a gift. The edge retention is great, and yet it’s nicely tough too. That makes it great, especially if you’re experienced at sharpening knives. If you’re a newbie who doesn’t really know how to sharpen knives, you’ll have a problem.
Then you also have to be very careful about corrosion. You’ll want to oil the knife constantly, and refrain from using it in wet conditions. It doesn’t have a lot of corrosion-resistance at all.
Even as a gift, the M2 steel knife is already problematic. But it’s simply a problem that you ought to avoid if you’re buying the knife. You have better alternatives for your money, with better performance and lower prices.
Pros & Cons of M2 steel
- Terrific edge retention
- Decent toughness
- Good material for metalsmithing practice
- M2 steel knives are rare these days
- Hard to sharpen
- Prone to corrosion
Conclusion
To be honest, there’s really no practical reason why you would want to go looking for an M2 steel knife. For one, they’re not easy to find, and they may be a bit more expensive even when you do find them. Manufacturers, for the most part, prefer to use other steels that are easier to work with.
Knife owners may love the edge retention and the decent toughness (especially in the Benchmade knives), but not at the price when you add the manufacturing costs. It’s also not easy to sharpen, and the corrosion resistance is negligible. You can certainly make use of M2 steel knives when you find them (or get them as gifts), but all in all, you have better options!