Maxamet is a super-hard, high-alloy powder metallurgy tool steel produced by Carpenter Technology Corporation. It is often described as a "bridge" between high-speed tool steel and cemented carbide.
In the knife world, Maxamet is famous for having some of the highest edge retention ever achieved in a production knife.
Key Characteristics
Insane Edge Retention: Maxamet is packed with a high volume of tungsten and vanadium carbides. It holds a sharp edge for an incredibly long time, outperforming almost every other steel except for specialized monsters like Rex 121 or 15V.
Extreme Hardness: It is typically heat-treated to an immense 68–70 HRC. This makes the blade incredibly rigid and virtually immune to edge rolling.
Very Low Toughness (Brittle): Because it is so hard, Maxamet is very brittle. It is highly susceptible to chipping or snapping if dropped or used for prying. It is a dedicated slicer and must be handled with care.
Non-Stainless (Semi-Stainless): With only 4.75% Chromium, Maxamet will rust and stain. It develops a dark grey or blue patina very quickly, especially when cutting acidic foods. It requires regular oiling to prevent red rust.
Extremely Difficult to Sharpen: Due to its hardness, standard sharpening stones are often ineffective. Diamond abrasives are required to maintain or repair an edge on Maxamet.
Chemical Composition
The "secret" to its hardness is the massive amount of Tungsten and Cobalt:
Carbon (C): 2.15% (Very high for hardness)
Tungsten (W): 13.00% (Provides extreme heat and wear resistance)
Vanadium (V): 6.00% (Creates hard carbides for edge life)
Cobalt (Co): 10.00% (Strengthens the matrix to support 70 HRC)
Chromium (Cr): 4.75%
Common Applications
Spyderco Knives: Spyderco is the most prominent user of Maxamet, offering it in models like the Para 3, Sage 5, and Manix 2 (identifiable by their dark grey handles).
High-Speed Industrial Cutting: Its original purpose was for industrial rollers and cutters that operate at high speeds and temperatures.
Maxamet vs. K390
Maxamet has better pure edge retention and is much harder (70 HRC).
K390 is significantly tougher and more reliable for daily use, even though it also rusts.