A "20-degree class" knife refers to a blade sharpened at a 20∘ 20∘ angle per side. This category—standard for most Western and American-style knives—strikes the optimal balance between sharpness and durability, making it highly resistant to chipping and ideal for heavy-duty daily tasks.
The best way to tell is by asking the manufacturer of the knife. As a general guide, European/American knives manufactured before 2010 have 20 degree edges while Asian style knives have 15 degree edges. However, there are exceptions to this rule of thumb.
Finding a 20 Degree Angle to Sharpen a Knife
When nothing else is available, we've found that folding a piece of paper twice can serve as a good guide to finding the proper angle. When you fold a piece of paper twice, the resulting angle is 22.5 degrees.
A 20-degree angle (per side) is the standard factory edge for most traditional Western, European, and American knives. This includes the majority of outdoor, pocket, and everyday carry (EDC) knives, as well as general-purpose kitchen cutlery.
The blade- edge angle for all Zwilling J.A. Henckels cutlery, with the exception of santoku knives, is 15 degrees on each side (30 degrees total).
Victorinox recommends sharpening your Swiss Army Knife at 15-20 degrees per side. If you're going to be using your pocket knife for delicate slicing tasks, like cutting fruit or slicing open envelopes, then pick an angle closer to 15 degrees.
German knives are sharpened at approx 20-22 degrees making the edge more durable but less prescise. The grit used here is commonly not above 800. The honing steel is used to true the edges of these blades. Japanese knives are made with a thinner blade and are ground to a more precise edge.
In the sharpening phase, we do not recommend any current WD-40® Brand Products although some may be used later for storage & protection. For sharpening stones the lubrication can come from water or oil.
Sharpen your knife at 20 degrees if you prioritize slicing ability and everyday tasks. Choose 25 degrees if you need a durable, robust edge built to handle heavy-duty abuse.
On Wüsthof European-Style knives, the blade edge angle has been reduced to 28 degrees (14 degrees per side), while Asian-style Santoku, Nakiri and Chai Dao knives have a blade edge angle of 20 degrees (10 degrees per side).
The ideal sharpening angle for a butcher knife is 15∘15 raised to the composed with power𝟏𝟓∘ to 20∘20 raised to the composed with power𝟐𝟎∘ per side (creating an overall edge angle of 30∘30 raised to the composed with power30∘ to 40∘40 raised to the composed with power40∘). This range provides a balance of razor-sharp slicing performance and edge durability.
Gordon Ramsay primarily uses a traditional honing steel (or sharpening rod) to maintain knife edges before use, emphasizing safety and consistent 45° angles. While he often uses professional whetstones for deep sharpening, modern demonstrations (and fan-used products) have shown the Tumbler Rolling Sharpener to be highly effective for achieving a razor-sharp edge on his knives.
The sharpest practical knife angle for everyday tasks is 10° to 15° per side. Lower angles create thinner, razor-like edges, but they are more fragile and prone to chipping. The ideal angle depends on the type of knife and what you are cutting.
To measure a 20-degree angle, you can use a traditional protractor for precision or alternative geometric methods if a protractor isn't available.
You can do both, depending on your equipment and personal preference. There is no single "correct" method, as both edge-leading (push) and edge-trailing (pull) strokes serve specific purposes.
We tend to grind to 13-16 degrees per side. If you match the existing edge angle and hold the knife against the stone to cut evenly across the edge grind, you will produce an edge with a similar angle.
Finding a 20-degree angle for knife sharpening can be done by using a standard marker to verify your work, using a stack of 4 nickels as a physical height guide, or using the "technique of halves" to find 20° freehand.
There is no set number of strokes to sharpen a knife. It depends entirely on how dull the blade is and the grit of your stone.
Cutting boards made of glass, granite, ceramic, or your dinner plate may look stylish or convenient, but they are the fastest way to destroy a knife's edge. These surfaces are harder than your knife's steel. So every time your blade contacts them, it suffers microscopic edge deformation, chipping, or even rolling.
Butterfly knives (or balisongs) are illegal in many areas because they are categorized as dangerous, easily concealed weapons that can be deployed rapidly with one hand. Lawmakers often associate their flashy nature with gang activity, intimidation tactics, and pop-culture violence.
Neither steel is objectively "better" overall; they simply excel at different things. The choice depends on your priorities: German steel is better for heavy-duty durability and low maintenance, while Japanese steel is better for razor-sharp precision and edge retention.
Chefs primarily sharpen their knives using a whetstone, which requires manually grinding the blade at a consistent 151515 to 202020-degree angle to reshape the edge. For daily maintenance before or after every shift, they use a honing rod (or steel) to realign the microscopic teeth of the blade.
Legal situation in Germany
The use of fixed knives with a blade length of over 12 cm, of cutting and stabbing weapons, as well as knives that can be locked with one hand, is regulated in Section 42a of the Weapons Act (Weapons Act), which prohibits the use of apparent weapons and certain portable objects.