CPM S30V stainless steel is developed by Crucible Industries while Maxamet is developed by Carpenter Technology, it is also referred to as Car Tech Micro-melt Maxamet.
S30V and Maxamet are two high-performance steels produced via powder metallurgy that differ significantly in their properties and performance in knives.
The key difference between them is that Maxamet achieves an ultra-high hardness of 68-72 HRC while S30V reaches 58-64 HRC.
This extreme hardness gives Maxamet unparalleled edge retention but makes it very brittle and difficult to sharpen.
S30V stainless steel on the other hand provides a better balanced combination of hardness, toughness, and corrosion resistance.
Maxamet vs S30V Steel At A Glance
| Property | S30V Steel | Maxamet Steel |
|---|---|---|
| Hardness | Decent hardness (58-64 HRC) | Ultra-high hardness (68-72 HRC) |
| Edge Retention | Good edge holding suitable for most tasks | Excellent edge retention for very demanding uses |
| Toughness | Retains decent toughness for better resilience | Very low toughness makes it prone to chipping |
| Corrosion Resistance | Good level provides versatility across environments | Poor corrosion resistance requires more maintenance |
| Sharpenability | Moderate difficulty to sharpen at ~60 HRC | Extreme hardness makes sharpening very difficult |
| Cost | Moderate cost as a common premium knife steel | High cost due to specialized nature |
Hardness
Maxamet is vastly harder compared to S30V steel. Maxamet can attain a hardness between 68-72 HRC when properly heat treated, while S30V reaches a maximum hardness of around 58-64 HRC.
The ultra-high hardness of Maxamet steel is enabled by its very high alloy content including 10% cobalt and high 6% vanadium.
This allows Maxamet to be heat treated to harness levels approaching those of cemented carbides. S30V cannot match this hardness level due to its lower alloy content.
The extreme hardness gives Maxamet unparalleled edge retention and wear resistance. However, S30V steel offers decent hardness while maintaining better toughness and grindability.
Other high-hardness steels like Rex 45 steel fall between the two in hardness, reaching around 66 HRC maximum.
For knives, Maxamet’s extreme hardness results in incredible cutting ability but with significant drawbacks in other areas. CPM S30V provides adequate hardness balanced with other important properties.
CPM S30V can make tough, well-rounded knives, Maxamet knives have amazing edge-holding ability but significant brittleness and maintenance issues.
Edge Retention
S30V and Maxamet differ significantly in their edge retention and wear resistance, which greatly affects their performance in knives.
Maxamet has vastly superior edge retention and wear resistance compared to S30V. In CATRA edge retention testing, Maxamet scored 222 relative to 440C at 100, whereas S30V scored only 145%.
Maxamet can attain over 70 HRC hardness versus 60-64 HRC for S30V. The high vanadium carbide content and hardness give Maxamet outstanding abrasion resistance.
In knives, Maxamet will maintain its edge for much longer under cuts and slices compared to S30V. Maxamet will far outlast S30V in extended cutting tasks against abrasive materials.
However, the extreme wear resistance comes at the cost of other aspects like toughness and sharpenability. S30V offers sufficient edge holding for most tasks while maintaining better balance. But for pure edge retention and abrasion resistance, Maxamet is vastly better than S30V.
Toughness
When it comes to toughness, S30V steel has higher toughness compared to Maxamet steel.
In Transverse Charpy C-notch Testing, S30V achieved toughness values around 10 ft-lbs which is four times greater than that of 440C, yet 440C has better toughness than Maxamet steel.
The higher attainable hardness of Maxamet, reaching up to 72 HRC, leads to its low toughness and brittle nature.
S30V steel maintains decent toughness in the 58-64 HRC range. The greater toughness of S30V means it is more resistant to chipping and cracking when subjected to impacts and lateral forces.
Maxamet extreme brittleness makes it prone to chipping when used for demanding tasks.
Additionally, S30V higher toughness allows for thicker and larger knife designs more suited for hard use, whereas Maxamet is limited to thinner geometries.
While Maxamet provides superior edge retention, CPM S30V steel is the clear winner for toughness.
S30V offers a better balance of moderate edge holding and higher toughness that makes it suitable for more rigorous knife applications.
Corrosion Resistance
S30V is a stainless steel with better corrosion resistance compared to Maxamet steel.
S30V contains 14% chromium, 2% molybdenum, and a small nitrogen addition which provides good corrosion resistance for knife steel.
Maxamet steel only has 4.75% chromium and no other significant corrosion-resistant elements.
With lower chromium and no other corrosion-fighting elements, Maxamet has very poor corrosion resistance compared to S30V stainless steel.
Pitting Potential Testing shows S30V achieves an average pitting potential of 250 milliVolts, which is even better than 154CM stainless steel.
Thus, S30V stainless steel knives better corrosion resistance provide more versatility and lower maintenance, an advantage over Maxamet steel knives.
But Maxamet can still perform well against corrosion with proper care and oiling.
Ease of Sharpening
S30V stainless steel is significantly easier to sharpen compared to Maxamet steel. Maxamet requires time and skill to resharpen once dull.
S30V reaches hardness in the 58-64 HRC range, which is challenging but very possible to sharpen with standard abrasives and equipments.
Maxamet, with its extreme hardness of 68-72 HRC and large vanadium carbides, makes it vastly more difficult to sharpen than S30V.
While S30V knives can be sharpened with reasonable effort and normal aluminum oxide sharpening tools, maxamet knives sharpening requires diamond stones or specialized abrasives.
Final Thoughts on Maxamet vs S30V
Having extensive experience with S30V steel over the years, I can say it is an excellent all-around knife steel that provides a great combination of properties for most uses.
S30V offers a good balance of hardness, edge retention, corrosion resistance, and toughness that makes it versatile for a wide range of knives.
I have only used Maxamet with a couple of knives belonging to friends. No doubt it had superior edge-holding ability, but at the cost of significant trade-offs in other areas.
Maxamet corrosion resistance was noticeably lower and it was extremely difficult to sharpen due to the ultra-high hardness.
For most knife users, I would readily recommend S30V as it has proven itself to be everything you could want for a well-rounded blade steel.
It provides sufficient cutting ability paired with easy sharpening and decent corrosion resistance.
Maxamet is an outstanding performer when sharp, but requires more specialized knowledge and equipment to sharpen and care for properly.
I would only recommend Maxamet for knife enthusiasts who are prepared to handle the extra demands required to utilize its unmatched edge retention.