Choosing the right sharpening angle is crucial for maintaining your knives and ensuring they perform at their best. This guide delves into the theory and practical advice on selecting the ideal angle for your knives, especially when using an angle guide for consistent results.
Before we explore specific angles, it’s important to understand how knife angles are typically described. Most knives feature a double bevel edge, meaning both sides of the blade are sharpened. When we recommend a 20-degree angle, for instance, it signifies sharpening each side to 20 degrees, resulting in a total edge angle of 40 degrees. This measurement refers to the angle at which you hold the knife against the sharpening stone or utilize your angle guide.
While double bevels are common, some knives, particularly traditional Asian designs, employ a single bevel. In these cases, one side might be sharpened to 20 degrees while the other remains at 0 degrees, creating a total angle of 20 degrees. However, the majority of Asian-style knives popular in Western markets are double beveled. If you are unsure about your knife type, it’s generally safe to assume it has a double bevel. Typically, Asian knives, designed with double bevels, are sharpened to a slightly lower angle, around 17 degrees per side.
Selecting a sharpening angle is essentially balancing sharpness and edge durability. The primary factor in determining the angle is your knife’s intended use. Will it be used for delicate tasks like shaving, precise filleting, general vegetable cutting, or more demanding tasks like carving or chopping wood? Each application demands a different edge profile.
Hardness vs. Toughness in Knife Steel
The quality of steel significantly influences a knife’s performance. Hardness and toughness are key properties of steel that directly impact edge retention and durability. Hardness, easily measured on the Rockwell C Scale, indicates a steel’s resistance to indentation and wear. Toughness, in metallurgy, refers to a material’s ability to absorb energy and resist fracture. Glass serves as a good example of a hard but not tough material – it’s easily broken.
In knife making, increasing steel hardness often decreases its toughness. Heat treatment is a crucial process where knife makers must carefully balance these properties. Steel that is too hard may become brittle and prone to chipping, while steel that is too soft won’t hold a sharp edge for long. This trade-off mirrors the decision-making process when choosing a sharpening angle: a finer angle yields sharpness but sacrifices some durability.
Understanding Sharpening Angle Ranges
Sharpening angles can be broadly categorized to suit different knife types and uses. Using an angle guide makes achieving and maintaining these angles significantly easier and more consistent.
Ultra-Fine Angles: Below 10 Degrees (Total Edge under 20 Degrees)
The most acute angles are reserved for tools designed for slicing exceptionally soft materials, where the edge is not subjected to heavy stress. Straight razors are the prime example, typically sharpened to approximately 7-8 degrees per side. These edges are incredibly delicate and prone to damage, but in their intended use, they avoid the kind of stress that would cause edge failure.
For sharpening straight razors or achieving similarly fine edges, water stones are highly recommended. Due to the delicate nature of these edges, grits coarser than 1000 are generally not advised.
Fine Angles: 10 to 15 Degrees (Total Edge 20-30 Degrees)
A 10 to 15-degree sharpening angle per side is quite acute for most knives. Resulting in a total angle of 20 to 30 degrees, this edge is exceptionally sharp but also more fragile. It is generally too delicate for knives used for chopping or tasks involving significant force. Harder steels, while offering better edge retention, can also be more brittle and susceptible to chipping at these acute angles. This range is ideal for knives used for slicing meats, filleting fish, or cutting soft fruits and vegetables, where a very smooth cutting action is desired.
High-end Japanese knives often fall into the upper end of this range, around 15 degrees per side, and are typically made from harder, high-quality steel. When sharpening knives in this category, using quality sharpening stones is recommended to effectively cut the hard steel without being overly aggressive. Traditional water stones are frequently recommended for Japanese knives due to their fine and controlled sharpening action.
Moderate Angles: 15 to 17 Degrees (Total Edge 30-34 Degrees)
Many Japanese knives and contemporary European/American cutlery come from the factory sharpened to 15 to 17 degrees per side. This range, creating a total edge angle of 30 to 34 degrees, offers a good balance between sharpness and durability. It provides a noticeably sharper edge than wider angles while still retaining reasonable resilience. For knives originally designed with a 20-degree edge, sharpening to this lower angle is often the minimum recommended for maintaining adequate durability.
Various sharpening tools are suitable for these angles, including powered sharpeners, sharpening stones, and guided sharpening systems, especially those that incorporate an angle guide for precision.
Standard Angles: 17 to 22 Degrees (Total Edge 34-44 Degrees)
The 17 to 22-degree range is versatile, encompassing most kitchen knives, pocket knives, and outdoor knives. Japanese manufacturers often sharpen to around 17 degrees, while Western knives commonly use a 20-degree angle per side. A 20-degree angle is often considered a sweet spot for general-purpose knives, offering a good compromise between cutting performance and edge stability. Kitchen knives sharpened to 17-20 degrees perform very well and remain sufficiently durable for typical kitchen tasks. For pocket and outdoor knives, a 20-degree angle is on the sharper end of ideal, prioritizing a balance of sharpness and resilience for varied use.
A wide array of sharpeners can handle these angles effectively. Powered sharpeners, sharpening stones, and guided systems are all appropriate, with guided systems offering increased precision in maintaining the desired angle.
Durable Angles: 22 to 30 Degrees (Total Edge 44-60 Degrees)
In this range, knife edges become significantly more durable. Pocket knives and hunting knives, which often endure more demanding use than kitchen knives, benefit from these wider angles. While the ultimate sharpness might be slightly reduced (though often imperceptible in everyday use), the edge’s resistance to rolling or chipping is greatly enhanced.
Sharpening tools capable of achieving these angles include powered sharpeners, sharpening stones, and guided sharpening systems.
Heavy-Duty Angles: Over 30 Degrees (Total Edge Over 60 Degrees)
Any edged tool or knife sharpened beyond 30 degrees per side will prioritize durability over fine cutting ability. The cutting performance will be noticeably reduced, but the increased robustness is advantageous when force is needed for cutting. While not ideal for most knives, tools like machetes, cleavers, or axes, which require extreme durability and are often made of softer steel, perform well with a 30-degree or wider angle.
Conclusion: Choosing Your Angle and Using an Angle Guide
Selecting the correct sharpening angle is a balance between sharpness and durability, primarily dictated by the knife’s intended use. Utilizing an angle guide during sharpening is highly recommended, especially for beginners or those seeking consistent, professional results. Angle guides ensure you maintain the chosen angle throughout the sharpening process, leading to a more uniform and effective edge. By understanding these angle ranges and using the right tools, including angle guides, you can optimize the performance and longevity of all your knives.
We at Sharpening Supplies are dedicated to providing expert advice and quality products to help you achieve the best possible results in knife sharpening. Explore our sharpeners and resources to find the perfect tools for your needs. The Sharpening Supplies Team
