Is CPM M4 steel good knife steel? Details CPM M4 Steel Review

CPM M4 steel, commonly known as M4, is high-speed tool metal manufactured by Crucible Industries,, a US company that follows the Compacted Powder Metallurgy.

It has high levels of Vanadium, Tungsten, and other elements that give it wear resistance and toughness. It is superior to M2, M3, M7, and M7 steels.

This steel is a popular choice for custom and premium knives due to its improved toughness and wears resistance. It is also more expensive than other types of standard steel.

CPM M4 is used to make knives, cold tools, punches, dies, broaching, and other items.

CPM M4 Steel Chemical Composition

  • Carbon C 1.42%: Enhances edge retention, hardness, and tensile strength. It increases steel resistance to wear and abrasion as well as corrosion.
  • Chromium Cre 4.00%: Formation Chromium carbide. This increases the hardness, tensile, and toughness of your blade.
  • Molybdenum Mo 5.25: It increases machinability and hardness.
  • Vanadium V 4.00% – It increases wear resistance and toughness as well as improves corrosion resistance. Vanadium V 4.00%: This high vanadium content gives M4 an advantage over steels that rely on Chromium Carbides for wear resistance.
  • Tungsten W 5.5% Increases wear resistance and hardness and is most commonly added to tool steel.
  • Manganese Mn 0.3%: Increases hardness and brittleness.
  • Silicon Si 0.55%: Increases strength and heat resistance.
  • Phosphorus P 0.033%: Increases hardness and machinability.
  • Sulfur S 0.06%: Increases machinability.

Properties of CPM M4


The Rockwell hardness scale indicates that CPM M4’s hardness ranges from 63.5 to 65.5 HRC. High levels of carbon are responsible for this high hardness.

This steel’s hardness is responsible for the steel’s outstanding wear resistance and edge retention.

Edge retention

CPM M4 steel is extremely hard and retains its edge well. It retains edges better than other popular steel types.

The CPM M4 knife range will provide you with a sharp and long-lasting knife.


You may have heard or read somewhere that hard steels are weak in toughness. However, this is not true for CPM M4 steel, which offers exceptional toughness.

This steel is very hardy and durable. Its strength comes from its carbon and vanadium compositions, as well as the CPM method used to produce it.

CPM M4 knives are designed to meet the needs of consumers who want knives that don’t break, chip or bend under stress and tension.

Wear resistance

Wear resistance is another area where the steel shines, which is also linked to its Vanadium-Molybdenum composition.

Knives made from this steal are extremely tough and durable, even when used in abrasive applications.

Corrosion resistance

CPM M4 steel does not have the same chromium content as stainless steel. This makes it susceptible to corrosion and rusting.

Knife-making steels should be resistant to corrosion, as knives are often exposed to acidic and humid environments that activate rusting.

This should not deter you from purchasing knives made of this steel. They will last a lifetime if you take care of them.


M4 is a hard steel but easy to sharpen. You should be able easily to achieve a sharp edge with simple sharpening tools.

This steel is recommended for knife users who don’t have the necessary skills to sharpen knives.

Equivalents to CPM M4

CPM M4 steel vs S30V

M4 steel is superior to S30V steel for edge retention, toughness, and ease of sharpening. S30V steel shines in corrosion resistance, as it contains more Chromium.

CPM M4 VS D2 Steel

Both D2 and M4 steels offer excellent edge retention, toughness, wear resistance, and edge retention. They also have poor corrosion resistance.

M4 steel is more difficult to sharpen than D2 steel and can hold an edge for longer.

M4 vs. M390

Both types of steel offer similar performance in terms of both edge retention as well as toughness. M390 steel has better corrosion resistance and wears resistance.

Can CPM M4 steel be used to make knives?

CPM M4 is one of the most popular knife steels. It is very sharp and has excellent edge retention. However, it is not resistant to corrosion. This can be easily fixed with proper care.

About the author

Hi, my name is Jaba Ray. I'm a knife expert and researcher. I am the creator of, your one-stop site for everything related to knives. I love people who need suitable steel or knife for their cook because I'm also a food lover. I work with a team of people who've always had a passion for knives and blades on this site.

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