knifeopedia

Highly alloyed (high speed) powder steel

 

All steel in this category is powder steel and has been developed for use in tools to guarantee excellent (hot) wear resistance in high-speed cutting applications. It usually has a complex chemical composition with large amounts of carbon and elements that form hard and thus wear-resistant carbides, such as Vanadium and Tungsten. Most steel in this category (except S90-125V) is not stainless.

 

Steel types: Rex 121, Rex 86, Maxamet, S90V, S110V, S125V, 10V, 15V, HAP 40, HAP 72

 

Hardness: HRC 63-71

 

​Microstructure

• High to very high carbide volume

• Evenly dispersed and regularly sized carbides

• No large primary carbides

 

Advantages

• Can be hardened to extreme hardness

• Very good to excellent abrasion resistance and thus edge retention

• Can hold moderately low edge angles (not lower than 20°) without chipping and thus good sharpness potential

 

Disadvantages

• Very high material cost

• Difficult to sharpen and to grind, thus high production cost

• Not stainless (except S90V, S110V, S125V)

• Low to moderate toughness

 

Conclusion: Niche steel for knife enthusiasts that are very experienced in sharpening.

​

 

Stainless powder steel

 

This category includes stainless powder steel with a less complex composition and lower amounts of elements that form hard carbides. This makes it a little less wear resistant than the more highly alloyed counterparts, but easier to manufacture and sharpen, thus more suitable for use in kitchen knives used by regular consumers.

 

Steel types: ZDP189, Elmax, Elmax 2, S45V, S60V, M390, CPM154, RWL34, SG2, R2, MC63, MC66

 

Hardness: HRC 61-67

 

​Microstructure

• High to very high carbide volume

• Evenly dispersed and regularly sized carbides

• No large primary carbides

 

Advantages

• Very good abrasion resistance and edge retention

• Can hold moderately low edge angles (not lower than 20°) without chipping and thus good sharpness potential

• Moderate to good stain resistance in daily kitchen use

• Not too difficult to sharpen

 

Disadvantages

• High material cost

• Moderate to low toughness

 

Conclusion: good steel for top-of-the-line kitchen knives, with SG2 / R2 the most widely used.

​

​

Fine-carbide conventional stainless steel

​

Steel in this category may have been developed for use in razor blades, for which a very fine microstructure with small and evenly dispersed carbides is a key requirement. It typically is lowly alloyed and contains only C (0.6 – 0.7%) and Cr (13%), and can be heat treated to peak hardness of HRC63. As a result, the edge can be taken to very acute angles without chipping and rolling, for best sharpness and a good edge retention, similar to carbon steel, but with the added benefit of being stainless.

Some versions like 14C28N or Vanax use slightly lower amounts of C, but add N, resulting in similar hardness with increased corrosion resistance.

 

Steel types

• Without nitrogen: AEB-L, 13C26, FC61, X70Cr13

• Nitrogen-enhanced: 14C28N, Nitro-V, Nitro-B, Vanax, Chronidur 30, LC200N

 

Hardness: HRC 58-63

 

​Microstructure

• Very fine microstructure with small and evenly dispersed carbides

• Low carbide volume

 

Advantages

• Good edge retention at low edge angles

• Good stain resistance (excellent in case of Nitrogen-enhanced steel)

• Good toughness

• Moderate material cost

• Best sharpness potential

• Easy to sharpen

 

Disadvantages

• Moderate abrasion resistance

 

Conclusion: Excellent steel for high-end kitchen knives with best cutting performance.

 

 

High-carbon conventional stainless steel

 

Steel in this category has a carbon content between 0.75% and 1.1% and can reach a hardness well over HRC 60, which is a significant upgrade as compared to the HRC 55-57 in typical mass-market kitchen knives. However, in conventional steel with high carbon content, the microstructure typically includes larger primary carbides, which doesn't support keen edge angles and is thus a limiting factor in cutting performance.

 

Steel types: VG10, AUS10, 440C, 10Cr, 154CM, BD1N, VG1, VG5, AUS8, 440B, 19C29, 8Cr, N690, CMV60, X90CrMoV18

 

Hardness: HRC 58-62

 

​Microstructure

• Coarse microstructure with large to very large primary carbides

• Moderate to high carbide volume

 

Advantages

• Good abrasion resistance

• Good stain resistance

• Good toughness

• Moderate material cost

• Fairly easy to sharpen

 

Disadvantages

• Due to the primary carbides, can’t hold edge angles under 25° without increased risk of chipping and thus moderate sharpness potential

• Moderate edge retention at wider edge angles

 

Conclusion: Good steel for higher-end kitchen knives, with VG10 being the most popular and most recognised steel brand in this segment.

 

 

Mid-carbon conventional stainless steel

 

Such steel has a mid-level carbon content from 0.4% - 0.6% and typically 14%-18% Chromium, often alloyed with Molybdenum and Vanadium. It can be heat treated to a hardness high enough for decent cutting performance, but is soft and tough enough to withstand some misuse in the kitchen without chipping. It’s sufficiently corrosion resistant to survive some dishwasher cycles without staining. It’s also easy to forge, which is why it’s commonly used in forged German knives.

 

Steel types: 1.4116, 1.4034, 440A, AUS6, 6Cr, 1K6, X50CrMoV15, VG2

 

Hardness: HRC 54-58

 

​Microstructure

• Fine microstructure with small carbides

• Low carbide volume

 

Advantages

• Very good stain resistance

• Very good toughness

• Low material cost

• Easy to sharpen

 

Disadvantages

• Low abrasion resistance and edge retention

• Moderate sharpness potential as too soft to hold acute edge angle

 

Conclusion: Good steel for mid-range kitchen knives with good all-round properties, with 1.4116 probably the most widely used knife steel in the world.

 

 

Low-carbon conventional stainless steel

 

This category includes the most inexpensive steel used for making kitchen knives, with a carbon content of around 0.3%, typically around 13% Chromium and no other elements added to the alloy.

 

Steel types: 1.4028, 3Cr, 420J2, X30Cr13

 

Hardness: HRC 50-54

 

​Microstructure

• Fine microstructure with small carbides

• Very low carbide volume

 

Advantages

• Very good stain resistance

• Very good toughness

• Very low material cost

• Easy to sharpen

 

Disadvantages

• Very low abrasion resistance and edge retention

• Low sharpness potential as far too soft to hold acute edge angle

 

Conclusion: Steel for entry-level kitchen knives.

 

​

Carbon steel

 

Many knife enthusiasts swear by carbon steel, as it has the potential of reaching the highest sharpness, supported by the fact that the sharpest professional Japanese knives are made of carbon steel. But the lack of corrosion resistance makes it a high-maintenance steel for kitchen knives and a poor choice for casual users.

 

Steel types

• Pure carbon steel: White 1, White 2, 1095

• Alloyed carbon steel: Blue 1, Blue 2, 52100, O2

 

Hardness: HRC 59-66

 

​Microstructure

• Fine microstructure with small and evenly dispersed carbides, given proper heat treatment

• Lower carbide volume

 

Advantages

• Good edge retention at low edge angles

• Moderate to high toughness

• Moderate material cost

• Best sharpness potential

• Easy to sharpen

 

Disadvantages

• Moderate abrasion resistance

• Very low stain resistance

 

Conclusion: Steel for knife enthusiasts who want the best cutting performance and know how to take care of the steel.