What is CPM D2 Steel?
CPM D2 steel is a variant of D2 steel produced following the advanced crucible CPM technology. To get CPM D2, the regular D2 is powdered and re-smelted. The end product is steel with small-sized and evenly distributed carbides which has better edge retention and wear resistance.
With proper heat treatment, CPM D2 is easy to work with and forms blades that remain sharp even when used daily for tough applications.
The major downside of this steel is that it is not stainless steel. The amount of Chromium in its composition does not qualify it as stainless steel. Therefore, it will quickly rust and stain if not well-taken care of.
Let us look at the properties of knives made using this steel:
CPM D2 Composition
- Carbon C 1.55%: Increases the edge retention, hardness and tensile strength. It also improves steel resistance to wear, abrasion and corrosion.
- Chromium Cr 11.50%: Chromium Increases hardness, tensile strength and corrosion resistance of a blade.
- Molybdenum Mo 0.90%: Improves machinability and corrosion resistance.
- Vanadium V 0.80%: Forms hard vanadium carbide in combination with other elements that improve wear resistance.
- Manganese Mn 0.45%: improves the strength and hardness of steel. When the steel is heat-treated, hardenability is improved with increased manganese.
- Silicon Si 0.40%: Increases strength and heat resistance.
- Phosphorus P 0.03%: Improves machinability and hardness.
- Sulfur S 0.03%: Improves machinability.
Properties of CPM D2
CPM D2 Steel Hardness
The Rockwell hardness of CPM D2 is 59-61HRC as per the Rockwell hardness scale. Note that the hardness differs from the heat treatment used by the manufacturer. With this hardness level, you can be sure to get blades with good wear resistance and edge retention.
CPM D2 Steel Wear resistance
One of the properties you will love about CPM D2 is its excellent wear resistance. This property is associated with the fine carbides in its composition, in addition to high Carbon contents. Being an improvement of the D2, which is good in wear resistance, you can expect nothing but excellence when it comes to wear resistance from CPM D2.
Knives made from this steel can withstand abrasion even better than knives made from stainless high carbon steels.
CPM D2 Steel Edge retention
Another property that stands out in CPM D2 knives is edge retention. The high carbon and carbide density in its composition increase this steel’s hardness, which translates to excellent edge retention.
If you are out for a knife to be used on tough applications without the need for frequent sharpening, look into the varieties of CPM D2 knives.
CPM D2 Steel Toughness
CPM D2 is hard steel and therefore does not offer the best toughness. This is not to say that it is the worst out there, its toughness is better than D2. The increased toughness from the original D2 is attributed to the powder metallurgy process that reduces the carbide size.
Knives made with this steel can withstand tough applications like light chopping without chipping and breaking. However, for heavy cutting needs like batoning, it is better to invest in knives made from steel with better toughness than CPM D2.
Sharpening CPM D2 steel
CPM-D2 steel knives are not that easy to sharpen compared to the original D2, this is due to the high hardness and high wear resistance. The blades of this steel do not wear out quickly and therefore take longer to get sharp.
This is not to say that you will never be able to re-sharpen your knives, but it will take a lot of your energy and time.
CPM D2 Steel Corrosion resistance
CPM D2 is not stainless steel and therefore does rust, especially without proper care. A CPM D2 knife will need more care due to the low chromium content.
To protect CPM D2 knives from rusting, do not leave them in water. Ensure to wash and wipe them dry after use.
CPM D2 Steel Equivalent vs Other Steels
CPM D2 vs D2
CPM D2 steel is a variant of D2 introduced in the market in 2007. CPM D2 powder metallurgy production process results in finer carbides and therefore offers better wear resistance, edge retention, heat treatment, and toughness than D2. While CPM D2 has increased Chromium content, it is still not stainless and will require a bit of maintenance to avoid corrosion and rusting.
CPM D2 vs S30V
S30V and CPM D2 steel are two totally dissimilar knife steels. S30V is more refined steel with a great balance of elements in its alloy, it offers better performance than CPM D2 in almost all aspects. To begin with, S30V is high-end stainless steel with better corrosion resistance due to the high amount of chromium content in its alloy.
In terms of edge retention; S30V knife steel does outshine CPM-D2 as it contains a higher amount of vanadium that aid in the formation of hard vanadium carbides. The vanadium carbides are excellent when it comes to edge retention and hardness.
Where CPM D2 shines over S30V is toughness. A CPM D2 knife will be less prone to chipping and cracking when used for tough application than S30V. The improved toughness of CPM D2 is due to the low Hardness and the lack of a higher amount of Chromium carbides.
CPM D2 vs S35VN
CPM S35VN steel is an improved version of S30V steel with added Niobium in its composition. The improved alloy gives it better toughness than S30V. In comparison to CPM D2, the S35VN toughness level is slightly less, hence a CPM D2 steel knife will beat an S35VN steel knife in toughness.
S35VN steel is however stainless steel and beats the nonstainless CPM D2 in corrosion and rust resistance. S35VN will also offer better edge retention than CPM D2 due to the increased Vanadium elements in its alloy that aid in the formation of hard vanadium carbides.
S35VN steel offers a better balance of performance across the board and will be a better pick compared to CPM D2. Just like its counterpart S30V, it is slightly expensive but totally worth it.
CPM D2 vs CPM 154
CPM-D2 steel is not stainless steel as it contains low chromium elements. CPM 154 steel on the other hand is true stainless steel with a high amount of chromium in its alloy. A CPM 154 steel will be better in corrosion resistance than a CPM D2 knife blade.
The refined powder metallurgy process increased the toughness level of CPM D2 than the original D2, by doing so it surpasses CPM 154 in toughness. This can be attributed to low Chromium content in CPM D2 that present less chromium to form chromium carbides that are easily brittle.
The edge retention of CPM 154 is slightly better than that of CPM D2. The better edge retention is due to the high Rockwell hardness of CPM 154. Overall CPM 154 is better knife steel than CPM D2 knife steel as it provides a more balanced approach on all aspects.
CPM D2 vs M390
CPM D2 steel is produced by Crucible industries while M390 is produced by Bohler. M390 is one of the best premium steels out there. It offers incredible edge retention and wear resistance while still being stainless steel. With that said, Bohler M390 steel will beat CPM D2 in corrosion resistance, edge retention, and wear resistance.
CPM-D2 will however provide better toughness than M390 due to the high hardness level of M390 which makes it a bit prone to chipping. It will also be easier to get a sharp edge on CPM D2 faster and easier than it will be on M390 steel.
M390 steel knives are considered premium and expensive than most steels out there including CPM D2 due to their superior edge retention and corrosion resistance capabilities.
Is CPM D2 good knife steel?
CPM D2 steel is good knife steel because of its good wear resistance, edge retention, and great toughness. The major downside is that it requires extra care to prevent rusting because it is not stainless steel. It is worth noting that the CPM D2 steel composition is highly similar to that of CTS XHP steel.
The performance of CPM D2 and XHP is also highly comparable, only that XHP will offer much-improved corrosion resistance due to increase chromium content. There is a negligible difference when it comes to edge retention and toughness of these two knife steels. I would highly suggest taking a look at CTS XHP steel knives over CPM D2 steel knives.
Best CPM D2 Steel Knife
For me, the best CPM D2 steel Knife I have come across is the USA made Kershaw Dividend Green Assisted flipper. This modified drop point knife is highly unique as it combines two different steels through Kershaw’s proprietary Composite Blade Technology. The knife features Bohler N690 steel on the upper side and CPM D2 on the cutting edge side. The two steel tooth-like pattern fusion gives the knife an extremely beautiful appearance while maintaining excellent edge retention, toughness, and slicing performance.