There are a multitude of blade steels on the market today. When researching a knife, one question might be "Is there really a big difference in knife blade steel?". The short answer is yes. Another common question might be, "What is the best blade steel?". This question requires more thought and research and if you read the many articles on the internet it is quite subjective. There are no standard metrics. To help narrow down the field, take a look at some of the following considerations as it applies to knife blades.
Budget is certainly a consideration when buying a knife. Entry level steels like the 420 series fall into this category as well as AUS 6 and 7Cr13Mov for example. I would not say these blade steels should not be a consideration but they tend to be softer metals that require more frequent sharpening to maintain best performance. If you are looking at a knife in this category and are paying more than let's say $40.00 you might be paying too much. There does seem to be an exception here, Buck Knives uses a 420HC steel where they have an exclusive heat treating process that produces a fine blade with a Rockwell hardness of about 58. Reviewers on the internet seem to feel the Buck Knives 420HC is a fine product.
Generally, mid grade level steels contain higher chromium content making them more expensive. For the extra expense, these steels often exhibit better corrosion resistant properties and increased edge retention. Better edge retention means it will require less frequent sharpening to maintain a performance edge. Examples in this category might be AUS 8, 440C and 8Cr13MoV to name a few. These are good choices for everyday carry knives.
I had to stop myself from saying "best steel" here. The best steel for your knife takes into account it's intended use. That said, some of these "super steels" as they may be referred to are manufactured in Japan, (VG-10) and in the United States. One of the leading manufacturers, (not only) of these blade steels is Crucible Industries. If you have ever read the specification sheet for a knife and have seen CPM-154 or CPM-S35VN for example this is a Crucible product. CPM stands for Crucible Particle Metelurgy. With the addition of varying amounts of chromium and vandium along with their production process, these blade steels exhibit superior edge retention, ability to become extremely sharp and rust resistant. These metals require the least amount maintenance to keep a performing edge; however, they also require a little more effort at the sharpening table. These benefits do come at a premium cost and knives using these steels are more expensive.
Living in Florida there is a constant exposure to high humidity and depending on the use, exposure to salt water. Corrosion resistance is a factor in these extreme conditions at least a little more than a guy who lives in the deserts of Arizona.
Spyderco has developed a series of knives specifically for the purpose of working around water. The Spyderco Salt Series uses H1 and a product called LC 200N which they claim is completely rustproof
Another way knife makers battle corrosion is blade coatings.
- Titanium Nitride - Best
- Black Oxide - Offers medium corrosion resistance
- Black Paint - A low quality coating
The "Black Paint" option has a high probability of chipping and scratching
Kizer Knives for example offers their Begleiter model, (part of the Vanguard series) which has a VG-10 blade with a gray titanium coating. This knife runs about $52.00, (check the blades-edge.com website for current pricing).
SOG Knives is another manufacturer using blade coatings such as black Cerakote and Tintanium Nitride.
From my own personal experience, I have several D2 steel blades not one of the better corrosion resistant blades, but I keep a light coating of oil on them and have not had any trouble with rust.
Super Steel are not Everything!
It is hard not to get caught up in the "super steel" marketing but the truth of the matter is what is best is a balancing act between blade hardness, toughness and how you plan to use the knife. If you are looking to purchase an everyday carry knife, CPM-S35VN is an excellent choice. This type of knife is used for everyday tasks like cutting cardboard, plastic or maybe using the knife for food preparation. It will stay sharp for a long time. The fact is harder steels are more prone to chipping and cracking in contrast to softer, tougher steels that can be subjected to increased levels of impact and torsion. TOPS knives who produces heavy duty survival and fixed blade knives uses 1095 steel. It's a cost effective steel, tough, will take a good sharp edge and can be sharpened easily in the field. Because the steel is soft, it will take more effort to maintain a performance edge.
In closing here, really budget based steels like the 420 series, AUS 6 and 7Cr13MoV products for myself......... I steer clear of. There are just to many better choices these days. The mid grade steels like 440C, AUS 8 and 8CR13MoV are no problem and I think most reviewers would have no problem recommending these products. As far as the high end steels, these are great choices for everyday carry blades. A favorite of mine is CPM S35VN. While you do pay a premium, the satin grinds look awesome and the blade retains an extremely sharp edge for an extended period of time, (based on use of course). I also have many D2 and VG-10 blades that I am very happy with. I hope this provides a little help in narrowing down the field.
Ability to resist deforming when subject to stress and applied forces. Hardness in knife steel is directly correlated to strength and is generally measured using the Rockwell Hardness Scale.
Ability to resist damage like cracks or chips when subject to impact or sudden loads. Chipping is a knifes worst enemy and is never easy to fix. It usually includes grinding down the blade. As a rule of thumb, the harder the steel the less tough it will be.
Corrosion Resistance -
Ability to resist corrosion such as rust caused by external elements like humidity, moisture and salt. Note that a high resistance to corrosion does involve a sacrifice in the overall edge performance.
Edge Retention -
Edge Retention represents how long the blade will retain its sharpness when subject to periods of use. It's what everyone talks about these days but unfortunately the measurement of edge retention lacks any defined set of standards and so much of the data is subjective. For the writer, edge retention is a combination of wear resistance and an edge that resists deformation.
INFORMATION COURTESY OF KNIFE INFORMER AND CRUCIBLE INDUSTRIES
|Description||Edge Retention||Corrosion Resistance||Ease of Sharpening|
|M390 CPM 20CV||9||7||2|
|Vanadis 4 Extra||61||709||132||Bohler|
|PM 7.5-1.3-2.75 CrMoV||61||674||126||Bohler|