What is AUS 8 steel?

AUS 8 steel is a budget Japanese-made stainless steel belonging to the AUS series lineup, consisting of AUS 4, AUS 6, AUS 8, and  AUS 10. Aus 8 steel is sometimes referred to as AUS 8A or simply 8A.

Its performance is comparable to other blade steels like AISI 440B and the popular Chinese-made 8Cr13MoV stainless steel. Aus 8 stainless steel is produced by AICHI steel company.

Knifemakers highly favor it as it provides excellent balance in edge retention, corrosion resistance, and price. It is an easy steel to work on, and with good heat treatment, it can get up to the 60HRC mark.

AUS 8 Stainless Steel Composition

  • Carbon C 0.75%: Increases the edge retention, hardness and tensile strength. It also improves steel resistance to wear, abrasion and corrosion.
  • Chromium Cr 14.50%: Chromium Increases the hardness, tensile strength and corrosion resistance of a blade.
  • Molybdenum Mo 0.30%: Improves machinability and corrosion resistance.
  • Vanadium V 0.26%: Forms hard vanadium carbide in combination with other elements that improve wear resistance.
  • Manganese Mn 0.50%:  improves the strength and hardness of steel. When the steel is heat-treated, hardenability is improved with increased manganese.
  • Nickel Ni 0.49%:  improves strength and toughness. It increases hardenability but not as much as some of the other alloying elements in steel. It can enhance corrosion resistance in significant amounts
  • Silicon Si 1.00%: Increases strength and heat resistance.
  • Phosphorus P 0.03%: Improves machinability and hardness.
  • Sulfur S 0.03%: Improves machinability.

AUS 8 Steel Properties

AUS 8 Steel Hardness

AUS 8 steel has a Rockwell hardness of 58-59 HRC. The hardness of AUS 8 is highly dependent on the heat treatment technique. It is capable of achieving 60HRC with good heat treatment.

Benchmade knife company has proven consistently that their heat-treated AUS 8 steel blades can achieve 59- 60 HRC. This makes their AUS 8 stainless steel knives a very suitable budget offering.

AUS 8 Steel Edge Retention

Edge retention of AUS 8 steel is directly affected by the hardness. The higher the Rockwell hardness achieved in heat treatment, the better the edge retention of the steel. At the hardness of about 59 HRC, AUS 8 steel edge retention is considered good, above average. 

Its edge retention is similar to its Chinese copy 8Cr13MoV stainless steel and the popular highly stainless Spyderco salt series LC200N steel. It offers better edge retention than most low carbon alloys as it contains a bit of vanadium that enables the formation of hard vanadium carbides that are excellent.

Ease of sharpening AUS 8 Steel

In addition to edge retention, AUS 8 steel knives are easy to sharpen. A standard aluminum oxide abrasive sharpening tool can quickly give you an impressive edge that will last for a long. 

AUS 8 Steel Wear resistance

AUS 8 stainless steel contains a high amount of carbon and molybdenum in its composition, making it good in wear resistance. Irrespective of the usage, knives made from AUS 8 steel remain in good shape for a long time unless subject to constant aggressive sharpening.

AUS 8 Steel Corrosion Resistance 

AUS 8 steel contains high levels of Chromium (up to 14.50%), which qualifies it as stainless steel. It also includes other elements in its alloy like Nickel, which improves its corrosion resistance, ranking it among the top budget steels with high corrosion resistance.

AUS 8 stainless steel blade steel corrosion resistance is good, similar to that of 8Cr13MoV and 154CM steel. However, this does not take the knives off the rusting hook. Proper care and maintenance are critical to protecting them from rusting, especially in high humidity areas.

Is AUS 8 steel tough? 

AUS 8 steel toughness is better than most stainless steel out there. For context, AUS 8 steel toughness beats most crucible S series blade steels, including the popular S30V and S45VN.

Molybdenum and Nickel in AUS 8 steel alloy significantly boost its toughness. Knives made from this material are highly resistant to chipping, cracking, or breaking even under pressure. Its toughness is comparable to that of 26C3 Steel but is lower than the New Magnacut Steel.

AUS 8 Steel Machinability

the Sulfur and Molybdenum in this Japanese steel give it excellent machinability. Knifemakers find this type of steel easy to work with because it is easy to cut and can achieve a good finish without struggling.

Pros and cons of AUS 8 Steel

Pros

  • Easy to sharpen and stays sharp for long, making it easy to use
  • It has corrosion resistance features, making it safe for meal preparation
  • It has decent edge retention releasing you of the burden of frequent sharpening
  • It is tough; therefore, it can be used for hard cutting jobs without the fear of breaking.
  • Knives made from AUS 8 steel are affordable.

Cons

  • The knives become dull quick under consistent use.
  • The quality of the knives depends on manufacturer adjustments during production and daily usage.

AUS 8 steel vs. other steels

Is AUS 8 better than 8cr13mov? AUS-8 steel vs 8Cr13MoV

AUS 8 is slightly better than 8Cr13MoV on paper, however, in real life scenario, you can’t tell the difference. The biggest difference between them is that AUS-8 is a Japanese type of steel, while 8Cr13MoV is made in China. However, it is claimed that 8Cr13MoV was a carbon copy of AUS 8 steel.

Looking at the composition of 8Cr13MoV and AUS-8 steel closely, we see that AUS-8 has a bit more Nickel elements than 8Cr13MoV  which may enhance AUS 8 stainless steel property and toughness.

Their Rockwell hardness and edge retention are similar, so is their ease of sharpening. Either way, 8Cr13MoV can be termed as AUS 8 stainless steel equivalent.

AUS-8 steel vs 440C

440C stainless steel is a better blade steel than AUS 8 stainless steel in terms of edge retention and corrosion resistance. AISI 440C steel was regarded as a premium high carbon stainless back then but time has changed and it now is in the budget range just like AUS 8 stainless steel.

440C stainless steel offers better edge retention than AUS 8 steel due to the high amount of carbon in its composition which enables it to attain 60+ Rockwell Hardness.

The high volume of carbon enables the formation of a large volume of carbides which is good for edge retention.

AISI 440C steel also offers slightly better corrosion resistance than AUS 8  due to the higher percentage of chromium elements in its alloy composition. 

AUS 8 steel blade offers double the toughness of 440C steel blade. The mixture of high carbon and chromium also impacts 440C steel negatively when it comes to toughness.

The formation of brittle chromium carbides greatly reduces the toughness of 440C blade steel. 

AUS-8 Steel vs S30V Steel

The main difference between AUS 8 Steel and CPM S30V steel is that S30V steel is often regarded as premium steel while AUS 8 steel is budget steel. S30V steel offers twice the edge retention of AUS 8 Steel. It also beats Japanese AUS 8 steel in corrosion resistance.

S30V steel beats AUS 8 steel in edge retention due to several factors. First, S30V  has a Rockwell hardness of about 61HRC, while AUS 8 steel Rockwell hardness is about 59HRC. The increased hardness increases the edge retention of S30V over AUS 8 steel. 

Secondly, the production process of S30V steel allows the formation of a large number of hard vanadium carbides. The vanadium carbides significantly improve the edge retention of S30V blade steel over AUS 8 steel.

S30V blade steel also offers better corrosion resistance than AUS 8 blade steel due to its alloy composition balanced to produce vanadium carbides leaving enough chromium to improve its stainless steel properties.

AUS 8 steel, however, beats S30V steel in toughness due to its relatively low hardness and lack of large brittle carbides. It is also easier to sharpen AUS 8 knife steel compared to sharpening an S30V blade.

AUS 8 vs VG10

AUS 8  and VG10 are popular Japanese stainless steels. They both have very different alloy compositions. VG10 stainless gives better performance than AUS 8 stainless steel and is always regarded as premium Japanese blade steel due to its composition being fortified by vanadium and cobalt.

VG10 stainless steel achieves a higher hardness of up to 62HRC; this, in turn, gives it better edge retention than AUS 8 stainless steel.  VG10 steel edge retention is similar to Bohler N690 steel and crucible CPM 154 stainless steel.

VG10 stainless steel also offers better corrosion resistance than AUS 8 stainless steel due to the higher amount of chromium elements and the addition of Cobalt in its alloy composition. VG10 stainless steel corrosion resistance is like that of Japanese Super Gold 2.

AUS 8 stainless steel, however, beats VG10 stainless steel in toughness. AUS 8 offers excellent toughness and is suitable for knives that require demanding applications. AUS 8 Steel is also much easier to sharpen as it does not contain a huge volume of hard vanadium carbides.

AUS 8 steel vs D2 Steel

The main difference between AUS 8 steel and D2 steel is that AUS 8 steel is a stainless steel, while D2 steel is a non-stainless tool steel. Each of these two steels exhibits very different performances as blade steels. First, AUS 8 stainless will be more resistant to rust and corrosion than D2 steel because it is stainless with over 13% chromium elements in its alloy.

D2 steel is, on the other hand, is designed as tool steel, and for this reason, it exhibits extreme wear resistance properties. D2 steel can achieve a hardness of up to 62 HRC. With this hardness, it offers incredible edge retention.

The edge retention of D2 steel is better than that of Japanese AUS 8 blade steel and beats most stainless steel, including popular steels like CTS BD1N, Nitro V steel, and LC200N steel

However, Sharpening  AUS 8 steel knife will be easier than sharpening a D2 steel knife due to the low wear resistance of AUS 8.

AUS 8 knife steel also offers better toughness than D2 knife steel. The toughness of D2 is low and thus not suitable for knives that require tough applications. The toughness of D2 is even lower than  AISI grade 440C.

AUS 8 vs AUS 10

AUS 10 Stainless steel and AUS 8 stainless steel belong to the same Japanese AUS steel family. AUS 8 stainless steel falls between AUS 6 and AUS 10; it thus performs better than AUS 6 but is not as good as AUS 10 steel.

AUS 10 stainless steel tends to get a Rockwell hardness of 60, while AUS 8 gets 58 HRC mostly.

AUS 10 thus has better edge retention and wear resistance due to its improved alloy composition, which contains additional carbon elements. 

AUS 8 steel will, however, offer better toughness than AUS 10 steel. It will also be easier to sharpen AUS 8 steel than sharpening AUS 10.

AUS 8 is a more popular offering with various knife companies than AUS 10 steel as it is cheaper and gives a great balance between edge retention, toughness, and corrosion resistance.

AUS 8 vs 9Cr18MoV

The main difference between AUS 8 steel and 9Cr18MoV steel is that AUS 8 steel is Japanese-made stainless steel, while 9Cr18MoV steel is Chinese-made Stainless steel. Both steel fall in the budget category, with both offering almost similar levels of Hardness at around 58 – 60 HRC. 

Both blade steels achieve an almost equal amount of edge retention with this similar hardness level, particularly when sharpened to the same angle.

Both steels should not be sharpened at a too shallow edge as they won’t hold up well. 9Cr18MoV particularly will tend to roll edge faster due to it being less tough.

Japanese AUS 8 steel is tougher steel than 9Cr18Mov steel. AUS 8 steel will be more suitable for larger, longer blades than 9Cr18MoV as it is less likely to break and chip when these two blade steels are put head to head. 

9Cr18MoV stainless steel is better at corrosion resistance than AUS 8 stainless steel as it contains more chromium elements in its composition.

The ratio of carbon to chromium enables the adequate formation of carbides and some chromium left for corrosion resistance.

Having experience with both blade steels, I’d say the Chinese made 9Cr18MoV false somewhere between AUS8 steel and 440C stainless steel.

AUS 8 is easier to sharpen and tough, while 9Cr18MoV is more corrosion resistant and may get better edge retention when sharpened at a suitable angle.

Is AUS 8 stainless steel good for knives?

AUS 8 stainless steel is good budget steel for knives. It might not match the qualities of superior steel grades, but its sharpness, edge retention, machinability, wear resistance, and corrosion resistance make it an ideal choice for knives.

Conclusion

AUS 8 stainless steel features make it a good choice for knife makers. AUS 8 offers a good balance between edge retention and toughness and is good enough for long blades.

Although it is corrosion-resistant, you are advised to take care of the knife, primarily if you reside in humid areas.

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