Knife Steel Comparison: 7Cr17MoV vs 8Cr13MoV

When it comes to choosing the right knife steel, the options can be overwhelming, especially when comparing popular choices like 7Cr17MoV and 8Cr13MoV. These two steels are frequently debated among knife enthusiasts and manufacturers due to their unique properties and applications. Are you curious about which steel offers better corrosion resistance, edge retention, or overall toughness? This article dives deep into the chemical compositions, strengths, and best uses for each steel type, providing a comprehensive comparison to help you make an informed decision. So, which one will come out on top for your specific needs? Let’s find out.

7Cr17MoV vs 8Cr13MoV: Key Differences

Chemical Composition

The chemical composition of knife steels significantly influences their performance characteristics.

7Cr17MoV Composition

7Cr17MoV steel, with 16% to 18.5% chromium, offers excellent corrosion resistance, ideal for environments with high moisture and rust exposure. The carbon content in 7Cr17MoV is relatively low, between 0.60% and 0.75%, trading some edge retention for increased hardness and durability. Additionally, the inclusion of vanadium and molybdenum enhances both hardness and toughness, providing a balanced performance profile.

8Cr13MoV Composition

8Cr13MoV steel contains 13% to 14.5% chromium, offering good corrosion resistance, though slightly less than 7Cr17MoV. It has a higher carbon content, typically between 0.7% and 0.8%, which promotes better edge retention due to increased carbide formation. This balance makes 8Cr13MoV generally softer than 7Cr17MoV, with an HRC rating of around 58 to 59, yet it maintains a sharp edge longer due to the higher carbon content.

Hardness and Durability

7Cr17MoV Hardness

7Cr17MoV steel achieves a higher hardness level, usually between 60 to 63 HRC. This increased hardness translates to a more durable edge that can withstand significant wear and tear. However, the trade-off is a slight reduction in toughness, making the blade more susceptible to chipping under extreme conditions.

8Cr13MoV Hardness

In comparison, 8Cr13MoV steel is softer, with a hardness range of 58 to 59 HRC. This lower hardness allows the steel to be tougher and less prone to chipping, making it suitable for applications where resilience is essential. Despite its softer nature, the higher carbon content ensures better edge retention, advantageous for tasks requiring a consistently sharp blade.

Common Uses

Applications of 7Cr17MoV

For example, 7Cr17MoV is perfect for survival knives used in wet or rugged outdoor environments. The superior hardness and corrosion resistance make it ideal for heavy-duty applications. It is commonly used in outdoor and survival knives, where durability and resistance to environmental factors are critical. The steel’s toughness also makes it suitable for tactical and hunting knives, where the blade must perform reliably under strenuous conditions.

Applications of 8Cr13MoV

On the other hand, 8Cr13MoV excels in kitchen knives that need to stay sharp for slicing vegetables or meat. It is favored for applications where maintaining a sharp edge is crucial. Its excellent edge retention makes it a popular choice for kitchen knives, EDC (Everyday Carry) knives, and other general-purpose blades. The balance between corrosion resistance and ease of sharpening also makes 8Cr13MoV a versatile option for knife enthusiasts and professionals alike.

Conclusion

While 7Cr17MoV emphasizes durability and corrosion resistance, 8Cr13MoV focuses on edge retention and versatility, making each steel suited to different needs. By understanding the unique properties of each steel type, users can select the most appropriate blade for their specific requirements.

Knife Steel Properties

Corrosion Resistance

Corrosion resistance is essential for knife steels, especially those exposed to moisture or corrosive environments. The presence of chromium in the steel’s composition significantly enhances its ability to resist rust and staining.

Factors Influencing Corrosion Resistance

• Chromium Content: Higher chromium levels, typically above 13%, classify a steel as stainless. Chromium creates a protective oxide layer that resists corrosion.
• Carbon Content: While essential for hardness and edge retention, higher carbon levels can reduce corrosion resistance if not balanced with adequate chromium.
• Alloying Elements: Elements like molybdenum and vanadium also enhance corrosion resistance by stabilizing the protective oxide layer.

Edge Retention

Edge retention refers to a knife’s ability to maintain a sharp edge during use. This property is critical for knives that undergo extensive cutting tasks without frequent resharpening.

Factors Influencing Edge Retention

• Carbon Content: Higher carbon levels, along with elements like vanadium and molybdenum, form hard carbides that enhance edge retention.
• Heat Treatment: Proper heat treatment processes, including hardening and tempering, optimize the steel’s microstructure for superior edge retention.

Toughness

Toughness is a measure of how well knife steel withstands impacts without breaking. It is especially important for knives subjected to heavy or abusive use, where the blade might encounter hard materials or sudden impacts.

Factors Influencing Toughness

• Hardness: While higher hardness improves edge retention, it often reduces toughness. A balanced hardness level is essential for maintaining both properties.
• Grain Structure: Fine grain structures, achieved through controlled forging and heat treatment, enhance toughness by preventing crack propagation.
• Alloying Elements: Elements like nickel and silicon can improve toughness by enhancing the steel’s ductility and impact resistance.

Balancing Properties

Balancing corrosion resistance, edge retention, and toughness requires precise alloy selection and expert heat treatment. The specific application and intended use of the knife will determine the most suitable balance of these properties.

Comparing 7Cr17MoV and 8Cr13MoV with Other Budget Steels

Comparison with Other Budget Steels

440C

440C steel is a widely used budget-friendly option, valued for its balanced properties and ease of heat treatment. It typically contains around 16-18% chromium, providing good corrosion resistance, though not as high as 7Cr17MoV. The carbon content in 440C is relatively high, around 0.95-1.20%, which contributes to its hardness and edge retention. However, it is slightly less advanced compared to more recent super steels.

• Hardness: 58-60 HRC
• Corrosion Resistance: Good
• Edge Retention: Moderate
• Sharpening Difficulty: Easy
• Toughness: Moderate

AUS-8 and 14C28N

AUS-8 is another common budget steel known for its corrosion resistance and toughness. It contains approximately 13-14.5% chromium and 0.75% carbon, making it similar to 8Cr13MoV. AUS-8 is easier to sharpen and maintain, though it may not hold an edge as well as higher-end steels.

14C28N is often considered one of the best budget steels available, offering a great balance of properties. It contains 14% chromium and 0.62% carbon, along with nitrogen, which enhances its hardness and corrosion resistance. This steel is known for its high toughness and ease of sharpening, making it a favorite among knife enthusiasts.

• AUS-8:

• Hardness: 57-59 HRC

• Corrosion Resistance: Good

• Edge Retention: Moderate

• Sharpening Difficulty: Easy

• Toughness: Good

• 14C28N:

• Hardness: 55-62 HRC

• Corrosion Resistance: Above Average

• Edge Retention: Decent

• Sharpening Difficulty: Easy

• Toughness: High

Comparative Analysis

When it comes to corrosion resistance, 7Cr17MoV stands out with its superior performance due to its high chromium content, making it ideal for use in wet or humid environments. 8Cr13MoV, while still good, does not match the corrosion resistance of 7Cr17MoV. In comparison, 440C and AUS-8 also offer good corrosion resistance, with 14C28N providing slightly above-average performance.

In terms of edge retention, 8Cr13MoV excels thanks to its higher carbon content and vanadium carbides. It surpasses 7Cr17MoV in this regard, though it is more challenging to sharpen. 440C and AUS-8 provide moderate edge retention, while 14C28N offers decent performance that balances edge retention with ease of maintenance.

Regarding toughness, 7Cr17MoV is known for its robustness, making it suitable for heavy-duty applications. 8Cr13MoV, while slightly less tough, still performs well in everyday use. Among the other budget steels, 14C28N is particularly noted for its high toughness, whereas 440C and AUS-8 offer moderate toughness.

When it comes to sharpening, both 7Cr17MoV and AUS-8 are relatively easy to sharpen, making them convenient for users who frequently need to maintain their knives. 8Cr13MoV, with its higher hardness and edge retention, is more difficult to sharpen, similar to 440C. 14C28N, despite its excellent properties, remains easy to sharpen, adding to its appeal.

Conclusion

In summary, both 7Cr17MoV and 8Cr13MoV have distinct strengths, making them ideal for different uses. 7Cr17MoV is perfect for those prioritizing corrosion resistance and toughness, while 8Cr13MoV is better for tasks requiring excellent edge retention. When compared to other budget steels like 440C, AUS-8, and 14C28N, each steel type brings a unique set of properties, allowing users to choose the best option based on their specific needs and preferences.

Sharpening Techniques

Using a Sharpening Steel

A sharpening steel is an easy-to-use tool that helps keep your 7Cr17MoV or 8Cr13MoV knife sharp and ready for use. It doesn’t remove significant material, but it realigns the edge to maintain sharpness.

• Step 1: Hold the sharpening steel vertically on a stable surface, with its tip resting on a cutting board or another sturdy base.
• Step 2: Position the knife blade at an angle of about 20 to 22.5 degrees against the steel. Adjust the angle depending on the knife’s purpose; a smaller angle results in a sharper but less durable edge.
• Step 3: Starting near the handle, pull the knife down the steel at a 20–22.5-degree angle, moving toward the tip. Alternate sides with each stroke, repeating 5–10 times.

This method is particularly effective for quick touch-ups, especially for softer steels like 8Cr13MoV that may lose alignment faster.

Whetstone Sharpening

While a sharpening steel is great for quick touch-ups, a whetstone is the go-to tool for restoring a dull blade or achieving a razor-sharp edge. Both 7Cr17MoV and 8Cr13MoV respond well to this technique due to their balanced hardness.

• Step 1: Soak the whetstone in water for about 10 to 15 minutes before use. Ensure it stays moist during sharpening to reduce friction and prevent overheating.
• Step 2: Secure the stone on a stable surface and choose the appropriate grit. A 1,000-grit stone is suitable for general sharpening, while finer grits (e.g., 3,000 or higher) are used for polishing.
• Step 3: Hold the knife at an angle of 15 to 20 degrees. For outdoor or survival knives made of 7Cr17MoV, a slightly wider angle may enhance durability.
• Step 4: Draw the blade across the stone in a sweeping motion, starting at the heel and finishing at the tip. Apply even pressure and ensure the entire edge makes contact with the stone.
• Step 5: Flip the knife and repeat the process on the other side. Alternate sides every few strokes to maintain symmetry.
• Step 6: After sharpening, test the edge by gently slicing through paper or checking for a burr along the edge, which indicates proper honing.

Honing and Stropping

For fine-tuning and achieving a razor-sharp edge, honing and stropping are essential final steps.

• Honing: Use a fine-grit ceramic rod to further refine the edge after whetstone sharpening. Follow the same angle and motion as with a sharpening steel.
• Stropping: Stropping is the finishing touch that gives your knife a professional edge. By pulling the blade backward across a leather strop, you’ll remove tiny burrs and polish the edge to perfection. Alternate sides to ensure a uniform finish.

Best Practices for Sharpening

To maximize the lifespan and performance of knives made from 7Cr17MoV or 8Cr13MoV steel, follow these best practices:

1. Sharpen regularly to avoid deep dulling.
2. Use tools suited to your knife’s steel and purpose.
3. Maintain a consistent angle during sharpening.
4. Clean the blade after sharpening to prevent rust.

By adhering to these techniques, users can maintain the optimal performance of their 7Cr17MoV or 8Cr13MoV knives, ensuring a sharp, durable edge for various applications.

Choosing the Best Steel for Knives

Everyday Carry Knives

Choosing the right steel for everyday carry (EDC) knives requires a balance of properties. For versatile EDC knives that are easy to sharpen and maintain, 8Cr13MoV is an excellent choice due to its good edge retention and balanced properties. Its moderate hardness (58-59 HRC) ensures durability without being overly brittle, making it suitable for general-purpose use.

Budget-Friendly Options

If you are looking for budget-friendly knife steels, both 7Cr17MoV and 8Cr13MoV provide excellent value. 7Cr17MoV is particularly attractive for budget knives due to its high corrosion resistance, making it ideal for environments where the knife might be exposed to moisture. 8Cr13MoV, while slightly more expensive, offers better edge retention and is widely available in a variety of knife models. Both steels strike a good balance between performance and cost, making them popular choices for economical knives.

Specialty Knives

For hunting, survival, or tactical knives that face rigorous use, 7Cr17MoV is ideal due to its superior hardness and corrosion resistance. Meanwhile, 8Cr13MoV works best for kitchen and precision cutting tools, thanks to its excellent edge retention and easy maintenance.

Stainless Steel vs. High Carbon Steel

Choosing between stainless steel and high carbon steel depends on the intended use and maintenance preferences.

Stainless Steel Benefits

• High corrosion resistance, ideal for humid environments.
• Requires less maintenance.
• Suitable for kitchen knives, EDC knives, and outdoor use.

High Carbon Steel Benefits

• Superior edge retention, stays sharp longer.
• Greater toughness for heavy-duty tasks.
• Needs regular oiling and care to prevent rust.

Making the Final Choice

Ultimately, the best steel for your knife depends on your specific needs and preferences. For everyday use and budget-friendly options, 8Cr13MoV provides a well-rounded performance. For specialized tasks and harsh environments, 7Cr17MoV offers durability and corrosion resistance. Consider factors such as edge retention, toughness, maintenance requirements, and the specific application of the knife to make an informed decision.

Frequently Asked Questions

Below are answers to some frequently asked questions:

What are the differences between 7Cr17MoV and 8Cr13MoV?

7Cr17MoV and 8Cr13MoV differ primarily in their chemical composition and properties. 7Cr17MoV contains about 0.6% carbon and higher chromium content (~17%), offering excellent corrosion resistance and ease of sharpening but lower edge retention and more brittleness due to impurities. In contrast, 8Cr13MoV has 0.7%-0.8% carbon and less chromium (~13%), resulting in slightly lower corrosion resistance but better edge retention and hardness (58-60 HRC) due to higher carbon and vanadium content. The choice depends on whether you prioritize corrosion resistance and sharpening ease (7Cr17MoV) or edge retention and hardness (8Cr13MoV).

Which steel is better for everyday carry knives?

For everyday carry knives, 8Cr13MoV is generally the better choice due to its superior edge retention and balanced hardness and corrosion resistance. While 7Cr17MoV offers excellent corrosion resistance and is easier to sharpen, its edge retention is not as good as 8Cr13MoV. Therefore, if maintaining a sharp edge for longer periods is important, 8Cr13MoV is preferable. However, if ease of maintenance and higher corrosion resistance are prioritized, then 7Cr17MoV could be considered. Ultimately, the choice depends on the specific needs and preferences of the user.

How does 7Cr17MoV compare to other budget steels like 440C?

Compared to other budget steels like 440C, 7Cr17MoV offers superior corrosion resistance due to its higher chromium content, making it ideal for outdoor and survival knives. However, 440C outperforms 7Cr17MoV in hardness (58-60 HRC vs. 55-57 HRC) and edge retention, making it better suited for demanding tasks. While 7Cr17MoV is easier to sharpen and maintain, 440C requires more effort due to its higher hardness. Both are affordable, but 7Cr17MoV is often favored for budget-friendly options, particularly when corrosion resistance and ease of sharpening are priorities, whereas 440C is preferred for greater durability and edge performance.

Is 8Cr13MoV good for kitchen knives?

8Cr13MoV is a good choice for kitchen knives due to its balanced properties. It offers decent hardness (56-60 HRC) and edge retention, making it suitable for everyday kitchen tasks. While it provides adequate corrosion resistance thanks to its chromium content, proper maintenance is essential to prevent rust. Additionally, 8Cr13MoV is easy to sharpen, which is beneficial for frequent use. Although it may not match the corrosion resistance of 7Cr17MoV or the edge retention of higher-end steels, it remains a cost-effective and practical option for kitchen knives, especially for those prioritizing ease of maintenance and affordability.

How do I maintain the edge retention of these steels?

To maintain the edge retention of 7Cr17MoV and 8Cr13MoV steels, regular sharpening with a whetstone of 1000-2000 grit is essential, followed by honing with a leather strop to polish the edge. Using proper cutting surfaces like wooden or plastic boards can prevent premature dulling. Additionally, avoid using the knives for tasks they are not designed for, such as opening cans or cutting through bone. Regular honing with a honing steel and hand washing with immediate drying also help in preserving the edge. While 8Cr13MoV offers better edge retention due to vanadium carbides, it is slightly more challenging to sharpen compared to 7Cr17MoV.

What are the pros and cons of high carbon steel knives?

High carbon steel knives offer superior edge retention, toughness, and ease of sharpening, making them ideal for demanding tasks and frequent use. However, they are more susceptible to corrosion and require regular maintenance to prevent rust. Additionally, they can be brittle and may chip under heavy use. These pros and cons highlight the trade-offs between high carbon steel and budget steels like 7Cr17MoV and 8Cr13MoV, which offer better corrosion resistance but may not match the edge retention and toughness of high carbon steel, as discussed earlier in the comparison.