What Is The Best Steel Stock For Knife Making?
The topic of the best steel stock for knife making is an important consideration when creating quality cutlery. There are many factors that go into determining the “best” steel stock for any particular knife design and intended use. This includes properties like hardness, corrosion resistance, edge retention, toughness, and ease of sharpening. The ideal steel for a chef’s knife may be quite different than the steel used for a tactical combat knife. Beginner knife makers also have different needs than expert bladesmiths working with more advanced techniques and equipment. This content will provide an overview of popular knife steels, considerations for intended use, heat treating and manufacturing processes, budget constraints, and some final recommendations to help choose the optimal steel stock for your knife making project.
Carbon Steel
Carbon steel is a popular choice for knife making because it is hard and holds a very sharp edge. It generally contains between 0.6-1.5% carbon. The more carbon in the steel, the harder it becomes. According to The Wildest Road, carbon steel knives are typically sharper, harder, hold an edge longer, and are easier to re-sharpen compared to stainless steel.
Carbon steel knives do require more care than stainless steel. Without proper treatment, carbon steel is susceptible to rusting and corrosion. Proper oiling and sharpening is key to maintaining a carbon steel blade. Common grades of carbon steel include 1095, 52100, and 80CRV2. 1095 is a popular choice containing 0.90-1.03% carbon and is valued for its edge retention and ease of sharpening. 52100 has 1.0-1.1% carbon and is praised for strength and edge holding ability. 80CRV2 is harder than 1095 but not as tough. It contains 0.75-0.88% carbon.
According to Serious Eats, while carbon steel requires more care, it is technically stronger and sharper than stainless steel. For knife makers and users wanting maximum performance, carbon steel is an excellent choice. However, maintenance must be kept up to prevent rusting and corrosion.
Stainless Steel
Stainless steels are more resistant to corrosion but remember that stainless steels stain less, and most of them will still rust in the right conditions (https://www.bladehq.com/blog/knife-steel-guide/). The most common grades used in knife making are 420, 440, AUS-8/8A, 154CM, and S30V.
The strengths of stainless steel include:
– Good corrosion resistance
– Easy to maintain
– Tougher than high carbon steels
– Higher chromium content improves hardness, wear resistance, and maintains a sharp edge
The weaknesses include:
– Less edge retention than high carbon steels
– More difficult to sharpen
– Lower carbon content reduces wear resistance
Popular grades like 154CM and S30V offer a good balance of corrosion resistance and edge retention for EDC knives. Higher end powder steels like S35VN and S110V offer superior edge retention and hardness for knives that see heavy use (https://knifeinformer.com/discovering-the-best-knife-steel/).
Tool Steel
Tool steels are high carbon and alloy steels designed for tools that require extreme hardness, wear-resistance, and high-temperature strength. Tool steels contain various alloying elements like chromium, vanadium, molybdenum, and tungsten that improve hardness and toughness. They are used for making knives, chisels, molds, and dies.
The most popular tool steels for knife making include A2, D2, O1, and S7. A2 and D2 contain chromium, molybdenum, and vanadium for hardness and wear resistance. O1 has high carbon and manganese for strength and shock resistance. S7 has chromium and molybdenum for toughness and impact strength. Tool steels provide an excellent balance of hardness, edge retention, and ease of sharpenability for knives.
The strengths of tool steels are high hardness ratings around 60 HRC, exceptional edge retention and wear resistance, good corrosion resistance compared to carbon steels, and higher toughness than stainless steels. The weaknesses are they can be challenging to heat treat properly and require precise tempering. They lack the stainlessness of stainless steels and ease of sharpening of carbon steels.
Overall, tool steels offer an optimal combination of hardness, toughness, and edge retention for knives used in demanding applications. Popular grades like D2 and A2 provide excellent performance with good corrosion resistance. Proper heat treatment is crucial to harness the full potential of tool steels.
Damascus Steel
Damascus steel is a type of steel alloy that was originally used to make swords and knives in the Middle East. It gets its name from Damascus, Syria where some of the first Damascus steel blades were forged[1]. Damascus steel is recognizable by the watery or wavy light and dark pattern on the metal surface.
Damascus steel is valued for knife making because it has unique properties and characteristics. Some key strengths of Damascus steel for knives include:
- Hardness – Damascus has high hardness to maintain a sharp cutting edge
- Strength – The layered patterning provides added strength and resistance to shattering
- Flexibility – Damascus steel is tough but also flexible to absorb impacts
- Edge retention – The steel holds its sharp edge well during use
- Corrosion resistance – Damascus provides moderate corrosion resistance
- Aesthetics – The flowing patterns are beautiful and unique in each blade
Damascus steel does have some limitations as well. The major weakness is that modern forms of Damascus lack the exceptionally high carbon content and special carbide nanostructures that gave ancient Damascus steel its legendary properties[2]. While modern Damascus has many desirable characteristics, it is not significantly better in performance than other high quality tool steels.
Consideration of Use
How someone intends to use a knife plays a major role in determining the ideal steel. Different applications require different properties from the steel.
For kitchen knives, characteristics like corrosion resistance, ease of sharpening, and edge retention are critical. Most professional chefs prefer high-carbon stainless steels like VG-10 or SG2 that offer a good balance of these traits. Carbon steel can also work well for kitchen knives if properly maintained, but may require more frequent sharpening and care to prevent rust. Stainless steel alloys with at least 13% chromium, such as 420HC, are a minimum recommendation for kitchen knife blades since they are more stain and corrosion resistant. The best stainless steel for kitchen knives offers a combination of corrosion resistance, good edge retention, and reasonable toughness and ease of sharpening.
For hunting or tactical knives, hardness and toughness to withstand impacts are key considerations. Tool steels like D2, 154CM, or S30V are common choices for these applications. Highly hard and wear resistant steels like M390 and 20CV can also be suitable if toughness is not the top priority. For maximum toughness, carbon steels like 1095 may be preferable, at the expense of some hardness and corrosion resistance. The intended use of the knife determines the balance of properties needed in the steel.
Heat Treatment
Proper heat treatment is essential for optimizing the properties of steel for knife making. The main steps of heat treatment include annealing, hardening, and tempering. Annealing involves heating the steel above a critical temperature to soften it and relieve internal stresses from forging or machining. Hardening requires rapidly cooling the steel from the austenitizing temperature to form a very hard martensitic structure. Tempering then slightly reheats the quenched steel to achieve a balance of desired hardness and toughness for the intended use of the knife. The specific temperatures and methods depend on the steel composition.
For simple carbon steels like 1095 and W1, heat treatment usually involves normalizing at around 1650°F, quenching in oil when glowing red hot around 1500°F, and tempering around 400°F for an hour twice (Source). More complex tool steels and stainless steels require precise control of temperatures and quenching mediums to achieve optimal hardness, toughness and corrosion resistance. Common austenitizing temperatures range from 1750-2000°F depending on alloy content. Quenching can use oils, aqueous polymer solutions, or forced air for faster cooling (Source).
For the best heat treatment results, use a digitally controlled kiln and follow specified time-temperature guidelines for the type of steel. Adjust tempering time and temperature through testing to hone in on the ideal hardness and toughness for the intended use of the knife.
Manufacturing Process
The manufacturing process used to make the steel can significantly impact the properties and performance of the steel. There are two main methods used to produce knife steel:
The conventional method involves combining all the alloying elements like carbon, chromium, vanadium etc. with iron. This molten metal mixture is then poured into molds to form ingots or cast into bars. The ingots are then hot rolled or forged into billets, which are the starting material for knives. This method allows precise control over the chemical composition of the steel.
The other method is powder metallurgy. In this process, pure elemental powders of iron, carbon, and alloying elements are mixed together in precise ratios. This powder is compacted into a billet under high pressure. The billet is then heated to fuse the powder into a solid piece of steel. This results in a very homogenous composition. Powder metallurgy steels often have superior properties compared to conventionally produced steels.
The forging and heat treatment steps also affect the steel’s properties. Complex alloys with multiple alloying elements generally require greater precision in controlling temperatures and cooling rates during heat treatment. The grain structure can be refined by processes like hot forging. Overall, the entire production process must be carefully controlled to achieve the desired characteristics.
Sources:
https://www.couteau-laguiole.com/en/content/48-from-steel-bar-to-knife
https://www.popsci.com/story/technology/how-quality-knife-blades-are-made/
Budget
The cost of steel stock is an important factor to consider when selecting metal for knife making. Different grades and types of steel can vary greatly in price per pound. According to this source, an inexpensive carbon steel may cost around $10 per pound, while more premium alloy steels can cost $30-40 per pound or more. The manufacturing process and amount of alloying elements in the steel impact the price.
For hobbyist knife makers on a budget, carbon steels like 1084 and 1095 provide an affordable option, with 1084 ranging from $6-10 per pound according to this supplier. Entry-level stainless steels like 440C can also be a budget-friendly choice. However, top-tier knife steels like CPM-20CV may be prohibitively expensive for some hobbyists.
The intended use and desired characteristics of the knife should be weighed against material costs. While it’s tempting to opt for the most expensive steel, a more affordable steel may suffice depending on the application. Established knife makers suggest selecting a budget-friendly steel while learning heat treatment methods.
Recommendations
Based on the analysis of factors like hardness, edge retention, corrosion resistance, toughness, sharpenability, and price, some of the best all-around steels for knife making are:
CPM S35VN offers an excellent balance of edge retention, corrosion resistance, and toughness. It’s one of the most popular premium stainless steels, though it can be more expensive. CPM S35VN has high hardness (HRC 59-61) and can hold an edge very well while resisting wear and chipping (source: https://knifeinformer.com/discovering-the-best-knife-steel/).
154CM is a high quality stainless steel that’s tougher than other premium steels like S30V. It offers great edge retention and corrosion resistance while being easier to sharpen than other high-end steels. 154CM is an excellent choice for a well-rounded knife steel (source: https://www.reddit.com/r/knives/comments/yxfp74/best_blade_steel/).
1095 is a popular high carbon steel due to its combination of high hardness, easy sharpenability, and low cost. It holds an edge very well and is easy to sharpen, though it can rust more easily. For an affordable, well-performing carbon steel, 1095 is an outstanding choice.
For knife makers looking for a general purpose blade steel that balances key factors like edge retention, corrosion resistance, toughness, and cost, CPM S35VN, 154CM, and 1095 are excellent all-around options.