Review of AUS 8 Stainless Steel

The single most important component of a good knife is the steel used to make it. A tough, versatile, damage-resistant steel can make or break a knife’s performance, as well as give them their high-quality standards. Stainless steel is a popular alloy type because of its unparalleled resistance to rust, as well as its convenient and stress-free ease of maintenance. The high chromium, Japanese-made AUS 8 stainless steel is an extremely hard, rust-resistant metal capable of acquiring a razor-sharp edge to satisfy any knife-maker or lover. The exceptional balance of qualities offered by the steel sets AUS 8 aside from many other high-grade steels in its class, giving it countless reasons why you should look for it in a knife.

What is AUS 8 steel?

The Japanese-made AUS 8 steel is often considered an upper-range steel, comparable if not better than steels such as 440C, CM-154, and D2 steels. Given a proper heat treatment and hardened to the right level, which is usually around 58 to 59 HRC, it will perform satisfyingly and meet the standards of a true quality stainless steel. A well-rounded composition allows for this steel grade to reach high levels of hardness, toughness, wear (the sideways shifting of the metal from its original position) and corrosion (the gradual destruction of metals) resistance, as well as edge retention (the ability to retain its sharp edge).

Composition

This is a carefully balanced composition to ensure not just a great hardness, toughness, and harden-ability, but also the critically important qualities of wear, abrasion, and corrosion resistance that are vital in any good knife steel. Each of the above listed components in AUS 8 steel serve different and equally important purposes which, together, make it a quality steel superior to so many of the other steels in its class.

Carbon content in a steel will give it the hard-to-achieve quality of an increased edge retention, which cannot be attained through the use of other popular elements in stainless steels. Edge retention in a blade is so critical because it helps give the steel the attribute of keeping its edge for long periods of time, ensuring any blade made with it to be a dependable, steadfast knife that will not let you down.

In order to be classified as a stainless steel, a metal must have a chromium content of at least 10.5 percent- AUS 8 steel has a 14.5 percent chromium content. The benefits of the use of chromium include a significantly increased hardness and toughness, as well as a strong tensile strength (the ability to withstand maximum stress), wear, abrasion, rust and corrosion resistance. Chromium is one of the most beneficial components of a stainless steel due to these reasons, which add to its dependability as well as its ability to attain a razor sharp edge and last for very long periods of time.

In addition to adding to a steel’s tensile strength and corrosion resistance, manganese also contributes to AUS 8’s commendable grind-ability and harden-ability. Steels that are easy for welders to fashion make for better blades, and make them easier to sharpen when they get dull.

When added to steel and cast irons, molybdenum contributes to the steel’s weld-ability and corrosion and wear resistance. By increasing the steel’s lattice strain, the energy required to ruin the blade is augmented, making the steel significantly stronger and less susceptible to such damages. This ingredient is not commonly found in stainless steels, but is becoming more commonly used due to its low density and more cost-effective price, and has begun to replace the now less common ingredient of tungsten.

Another unique component of AUS 8 is nickel. When nickel is added to a stainless steel, the austenite structure of the iron is steadied. Although manganese does similar things to nickel, and nickel is generally more expensive, sufficient nickel content will weaken a steel’s corrosion resistance no matter how much manganese it has. Nickel also contributes to AUS 8’s laudable weld-ability, another reason why knife makers like it so much and prefer it over other high-grade steels.

Silicon is commonly found in stainless steels, offering an increased tensile strength to give those steels a greater maximum stress resistance. Consequently, knives using the silicon-rich AUS 8 will be rugged and dependable- able to go anywhere with you.

Vanadium, a new and innovative additive to quality stainless steels, not only dramatically increases AUS 8’s tensile strength, but enhances what few other elements can offer by adding to the steel’s impact strength, a key component in ensuring a knife’s ruggedness and adding a pure dependability that will give you an unquestionable confidence in the steel’s ability to take abuse and come out unscathed. Such imperviousness to damages makes AUS 8 steel such a great candidate for use in even the most rugged survival/bushcraft knives. Vanadium is also reported to make steels easier to sharpen.

Despite the quality of AUS 8 steel, it should not be thought to be a premium grade steel, such as S35VN, ELMAX, and M390 steels. AUS 8 is a high-grade metal that is in the ranks of steels such as 440C and 8Cr13MoV grade steels. Therefore, knives with AUS 8 steel will typically be more in the 30 to 150 dollar range depending on other factors included with the knife such as mechanisms and handle materials as well as overall workmanship, whereas knives with premium grade steels will fall more typically in the 150 to 500 range. These types of knives are ideal for outdoorsmen, hunters, and other knife-users who are looking for a quality blade in an affordable price range that will be dependable and serve its purposes well.
Why is AUS 8 steel so popular, who uses it, and for what purposes is it used?

Because of its superior composition, which allows for it to be so versatile and strong, AUS 8 has become popular among knife makers and knife companies, who use it to make many different types of blades.

Among the many knife companies which use AUS 8 steel in their knives, SOG uses the steel for many of their specialty knives, creating easy-to-handle knives which will be able to withstand significant abuse and perform satisfyingly. Ontario is another company that utilizes AUS 8 steel in its knives, having realized the metal’s potential for a worthy service to a knife. Cold Steel, a company that produces a wide variety of blades including, knives, machetes, and swords, is known to have often utilized AUS 8 steel in their tools and weapons in order to obtain the quality features that AUS 8 has been known to offer.

These knife makers and many more prefer this steel to others in its class for the reason that it can be “stamped,” as opposed to “forged.” Stamped knives are made from large sheets of stainless steel, able to be mass produced by a machine that stamps out the metal in the shape of a knife. Afterwards, the handle is added and the knife is sharpened and polished. This process makes knife-producing significantly more convenient and inexpensive than “forged” knives, which are created in a process where the raw metal is melted and shaped to the right size, then sharpened and polished- a longer and more expensive process.

AUS 8 steel is also very popular for use in machetes, with its tough and dependable qualities matching to what is looked for in a good machete. Ontario and United Cutlery are two companies which utilize AUS 8 steel in the blades of their machetes.

How does it score?

There are a myriad of tests done to determine the success of various steels; these tests measure everything from toughness to corrosion resistance to tensile strength. AUS 8’s results on such tests are probably a reason why the steel is so popular. When it comes to knives using the high-grade alloy, it did not take long for knife critics to realize the quality of AUS 8 steel, leading to many awards won by knives made of the high-grade metal.

Awards won by AUS 8 knives

• Outdoor Life’s 2010 Editor’s Choice for Survival Knives

o This award was won by SOG’s tactical “Seal Pup Elite” model, a serious tactical knife which claims to be supplied to many of the world’s elite military forces. Outdoor Life gave it an A+ in performance and design as well as an A in price and value. The thick, well balanced blade had an ergonomic, easy-to-grip handle that makes for a simple knife with all of the high-tech aspects found in modern knives, they said. The success of the knife “lies in its usefulness,” they claimed, and with AUS 8 steel used to make its blade, the knife is sure to perform to the rigorous standards set by Outdoor Life’s award.

• NTOA Tested and Approved, 2007

o This award was won as well by SOG’s “Seal Pup Elite,” and was given a 3.85 out of 5 overall score by the National Tactical Officers Association in a review that was published in the Tactical Edge journal. The tester said that “the blade is very sharp,” and was impressed at how it “retained its sharpness after abuse,” and even after jabbing the knife repeatedly into a dead tree, the point held up “without any damage or dulling.” Reportedly, the spine rasp cut through wood like a saw.

o This award was also won by SOG’s “Trident” model, which scored a 4.51 out of 5 as an overall score in a review that was also published in the Tactical Edge. The tester was incredibly positive in his review, making statements such as “this knife is flat-out awesome,” and said that he would recommend the knife to anyone as it is “one of the best I have seen.” With the Trident, he said, cutting was a breeze- with AUS 8 steel in its blade, it’s not very hard to see why!

• Gear Patrol’s Best Gear on Earth Award 2013

o This prestigious award was given to SOG’s “Flashback” model, a tactical knife claiming to be the “fastest assisted-opening blade available,” with the excellent edge retention, rust resistance, and sharpen-ability that can be found in many AUS 8 knives.

• Blade Show’s 2007 Collaboration of the Year Award

o The AUS 8 knife to win this award is called the “Kiku,” manufactured by none other than SOG, and is an official production collaboration between SOG and the Japanese knife company “Kiku Matsuda,” which is fitting because AUS 8 is a Japanese steel. Rugged and easy to handle, the Kiku is a true quality knife thanks to AUS 8.
How AUS 8 steel scored on tests

On an edge-testing test done by cliffstamp.com, AUS 8 steel scored very positively when tested for sharpen-ability. Spyderco’s AUS 8 Calypso Jr. model needed ten hard strikes into a butcher’s steel and five strikes on a ceramic rod to be fully sharpened, faster than the high-end VG-10 steel, and on par with another high-end steel that was tested- D2 steel.

On another edge-retention test, at a hardness of 58 HRC, AUS 8 was reported to have easily outperformed steels such as 400C, 154-CM, and VG-10 steels when they were at HRC’s of 58 and 59.
How does it compare with the other steels in its class?

In the class of mid-higher grade steels, AUS 8 is definitely up there with the best; the question is, how good is it really, and can it compare with some of the other steels accompanying it in its class.

AUS 4

This steel is made by the same company which manufactures AUS 8 and definitely shares many of its characteristics. A couple of differences, however, set AUS 8 aside from its counterpart. To begin, AUS 4 is much lower than 8 in its carbon content, therefore losing out on much of the edge retention offered by the critical ingredient. AUS 4 lacks the element of molybdenum, which is a key component to most of AUS 8’s features including its hardness, harden-ability, toughness, tensile strength, and resistance to wear, corrosion, and abrasion. The lack of this element significantly detriments AUS 4 and its ability to perform to the standards necessary in order to be on par with other high grade steels. Vanadium, as well, is found in AUS 8, but not in 4- vanadium being one of the few ways to truly increase the impact strength of a stainless steel. These ingredients give AUS 8 a certain ruggedness and dependability which simply cannot be found in its counterpart.

8Cr13MoV (of the MoV series)

This Chinese steel is often said to be very similar to AUS 8. It has a great value and is used by respectable knife manufacturers such as Spyderco and Kershaw, who have mastered the complicated heat treatment process to bring the steel to its full potential. When compared to AUS 8, it puts up a similar carbon content, at .8 percent vs. the AUS 8’s .75 percent. In regard to chromium and manganese, two important elements in stainless steel, both steels have similar contents, with AUS 8 pulling ahead ever-so slightly with 14.5 and .5 percent vs 8Cr13MoV’s 13 and .4 percent. The Chinese steel also contains slightly less silicon and vanadium than AUS 8, components which significantly contribute to a steel’s tensile and impact strength. Although these differences individually seem trivial, together they form a more distinct differentiation between the two steels.

Top AUS 8 folding knives

Although AUS 8 is used in many types of blades, survival/bushcraft knives are probably its main use. Below are two notable AUS 8 knives that will prove the quality of the high-grade metal alloy with their award-winning features and superior qualities.
SOG AE-04 Aegis

The name “Aegis” is a Greek word meaning shield, and with the features offered by the knife, it certainly lives up to its name. The blade itself is half-serrated at 3.5 inches of AUS 8 steel with a black “TiNi” finish to offer improved durability. When opened, the knife is 8.25 inches. Thanks to SOG’s unique cryogenic heat treatment, combined with AUS 8 steel, the knife has an incredible toughness and wear resistance, and is capable of taking a razor sharp edge. The blade’s handle is made of glass-reinforced nylon with a black finish, and is made to fit with ergonomic precision in your hand.

SOG’s “Assisted Technology” allows for fast and easy opening, offering a convenience that is only added to by a blade lock, anti-slip inserts, and SOG’s trademarked bayonet clip, which allows for the knife to rest securely in your pocket when not in use. The knife is 58 dollars, sitting in the middle of the pack price-wise for AUS 8 knives, making the knife both great quality-wise and cost-effective for avid outdoorsmen looking to get a great knife for a decent price.
SOG TF-7 Trident

The award-winning “Trident,” which scored a commendable 4.51 out of 5 on NTOA’s Member Tested and Recommended test, has a great design and the quality features that one would expect to find in a blade made of AUS 8 steel. The straight, 3.75 inch blade has a “tanto” shape with a hardcase black “TiNi” finish, and has the superior strength, wear, corrosion, and abrasion resistance that is so commonly found in knives with AUS 8 steel- the very reason that SOG so proudly uses it in so many of their knife models. The knife’s cutting groove will cut through anything from seat-belts to para-cord without having to open the blade.

Similarly to the Aegis, convenience was taken into account during the design phase of this knife, giving it features such as a reliable locking system, finger grips, a lanyard hole, a safety latch, and the knife’s unparalleled “Assisted Technology” opening system, which practically opens the knife for you once you begin the motion. The remarkable safety features offered by the Trident will balance eliminating the fear of unexpected opening with the ability for split-second, quick deployment that will give you confidence to bring this knife anywhere with you, and can be yours for just 60 dollars.

So for knife lovers and avid outdoorsmen, campers, and pretty much everyone else from military figures to fishermen- if you are looking for a rugged, quality knife at an affordable price, AUS 8 is the way to go. With all of the superior and convenient features that are offered by the metal, you can confidently buy your next AUS 8 knife with the absolute confidence that it will meet your every expectation and perform to the standards which can be expected of a true, high-quality stainless steel.

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