Folding Pocket Knife Steel: Hardness, Toughness, and Corrosion-Resistance

Whether you’re getting your first folding pocket knife or your fiftieth, now is a good time to learn a little bit more about steel.

The truth is, the steel used in the creation of a folding pocket knife is the number one determinant of its quality.

A knife with excellent fit and finish, great ergonomics, and quality construction, which is made from low-grade steel, is, well, low grade. It’s like a wall-hanger. It can look nice, but it can’t perform the job for which it was intended.

There are three main (high-level) criteria used to evaluate the quality of a knife steel. These are hardness (which corresponds to edge retention), toughness, and corrosion resistance, or how well the knife resists rust.

Old-timers will tell you that you can get at most two of these traits in a steel. Modern metallurgical advances have created super steels that offer all three – hardness, strength, and resistance to corrosion.

Here’s what you need to know.

Hardness (Edge Retention)
Carbon is the chief element that determines how hard a steel can be. The more carbon, and the more precise the heat treatment, the harder the steel will be.

Hard steels hold an edge for longer, but they’re also more brittle and at a higher risk of chipping, cracking, or breaking.

Toughness
Toughness refers to how strong a steel is, in terms of tensile and compressive strength. Toughness also refers to resistance to torsion and shear stresses, as well as to impulse.

Folding pocket knives made with tough steel are unlikely to snap, crack or chip. There are several elemental additives that improve the toughness of steel.

Corrosion-Resistance
A steel that is corrosion resistant is less likely to rust. Primarily, metallurgists add chromium to steel to improve corrosion resistance, although some modern steels use nitrogen.

Knives marketed as having stainless steel blades offer high resistance to corrosion.

Iron
Iron is the principal element in steel, responsible for the bulk of strength and integrity. Native iron is strong and tough, but not as strong or as hard as steel, and extremely prone to oxidation (corrosion).

Carbon
Carbon is a nonmetal added to iron that makes it become steel. The addition of carbon allows iron to form a unique, more rigid matrix that is much harder and stronger, which is known as steel.

However, the more carbon in the alloy, the more brittle the steel tends to be.

Chromium
The addition of chromium in a steel improves its corrosion resistance. Therefore, the vast majority of steel alloys contain some measure of chromium. However, the higher the chromium content, the softer the steel.

Nitrogen
Nitrogen is added to steel because it can form nitrides which improve the strength and wear resistance of the alloy. Nitrogen also can improve corrosion resistance.

Vanadium
The inclusion of vanadium in steel improves the grain structure of the steel, which in turn improves toughness and wear resistance. Vanadium also combines with carbon to form vanadium carbide, which increases the hardness of the alloy.

Manganese
Manganese is included in steel because it also helps improve the hardness, and therefore the edge retention, of the steel.

Molybdenum
Molybdenum is frequently included in steel alloys because it offers a number of significant benefits. This element improves not only hardness and toughness but also corrosion resistance since molybdenum does not readily oxidize at low temperatures.

Get a New Folding Pocket Knife at White Mountain Knives
Looking for a new folding pocket knife for EDC for cutting rope or detail work? White Mountain Knives has the EDC knife you need! They carry a wide range of models from top brands, including Buck, Spyderco, Benchmade, Gerber, and countless others.

They have everything you need for everyday carry in a folding knife collection that leaves nothing to chance. Whether you prefer liner lock or frame locking mechanisms, thumb studs, thumb holes or assisted open to make a knife easy to open, pocket clips, or free pocket carry, they have it all.

Visit their website at WhiteMountainKnives.com or at the above link to learn more and pick up a new piece of pocket candy today.

Leave a Reply

Your email address will not be published. Required fields are marked *

Busniess

Choosing a Space for a Home Battery Backup System

Determining that it’s time to outfit your home with a home battery backup is one thing. Then you potentially have to install an alternative energy system, determine how many batteries you need, what sorts of other electrical infrastructure are necessary (inverters, switches and more) and settle on a place for the batteries themselves. This short […]

Read More
Busniess

What Commercial Labs Actually Need From a Natural Gas Dehydrator

Water vapor in gas lines doesn’t give much warning. It builds inside compressors, analyzers, and flow meters over time until something stops working correctly, and tracing it back takes longer than it should. Commercial labs dealing with natural gas in quality control, calibration, or instrument supply lines run into this more than the incident reports […]

Read More
Busniess

Practical Kitchen Additions Worth Making This Year

If you spend any real time in your kitchen, you already know that the right upgrades pay for themselves in convenience, health, and everyday enjoyment. The best additions aren’t the flashiest gadgets that end up in a drawer by spring. They’re the practical, daily-use items that quietly improve how your kitchen runs. This year, one […]

Read More