Best Whetstones and Sharpening Methods for Outdoor Knives | A Whetstone Specialist Explains the Right Choice for Each Grind and Steel　

【Conclusion】 When sharpening an outdoor knife, there are two things you need to get right: know your knife’s blade grind and keep the sharpening angle consistent.

Once you understand these two points, even beginners can restore an outdoor knife using ordinary whetstones at home.

For your first stone, a #1000 medium-grit whetstone is all you need. The exception is high-performance powder steels such as S30V and M390, which are better sharpened with diamond stones.

This guide is for anyone who wants to sharpen their own camping, fishing, or outdoor knives. From a whetstone specialist’s perspective, we will explain sharpening techniques for different blade grinds, how to choose the right stone, differences between knife steels, rust prevention, field sharpening, and even the often-overlooked laws surrounding knife carrying.

If you are buying just one stone, start with a #1000 medium-grit whetstone.

What This Article Covers

• 1. First, identify your knife’s blade grind

  2. The basic principles of sharpening: angle, direction, and burr

  3. How to choose the right sharpening stone

  4. How to sharpen each blade grind

  5. How steel type changes sharpening difficulty

  6. Rust prevention and maintenance

  7. Emergency sharpening in the field

  8. Safety and knife-carrying laws

  9. What not to do

1. First, Know Your Knife’s Blade Grind

Unlike kitchen knives, outdoor knives come in several different cross-sectional blade shapes, known as grinds.

The grind determines how the blade should contact the sharpening stone, so identifying your knife’s grind is the first step before sharpening.

Diagram: The way the blade contacts the whetstone changes depending on the grind. Green indicates the area to sharpen.

Scandi Grind

Common on Mora knives and similar outdoor knives.

The bevel consists of one broad, flat surface. Simply place that entire bevel flat against the whetstone, and the sharpening angle is automatically set.

This is one of the easiest grinds for beginners to sharpen.

V-Edge / Secondary Bevel

Found on many commercially available knives.

A small secondary bevel forms the cutting edge. Hold the blade at approximately 10–15° per side and sharpen only this small bevel.

Convex Grind

A convex grind has a curved cutting surface.

It is best maintained with a leather strop or other sharpening method that preserves the curved profile.

Avoid aggressively sharpening a convex edge on a flat whetstone, as this can flatten the original geometry.

2. The Basic Principles of Sharpening | Angle, Direction, and Burr

The fundamentals are the same as sharpening a kitchen knife: maintain a consistent angle and properly remove the burr.

Understanding what sharpening is actually doing makes the entire process much easier.

The cutting edge is simply the line where the two sides of the blade meet.

When a knife becomes dull, that once-sharp intersection becomes worn into a microscopic flat or rounded surface.

Sharpening removes material from both sides until those surfaces meet again at a single, precise edge.

Every principle below exists to create that clean intersection.

Keep the Angle Consistent — The Most Important Rule

For a V-edge, aim for approximately 10–15° per side.

For a Scandi grind, simply place the entire bevel flat against the stone, so you do not even need to memorize an angle.

Why is consistency so important?

If the angle moves while sharpening, the stone may contact the “shoulder” of the bevel rather than the very apex of the edge.

You can sharpen for a long time without actually reaching the cutting edge—and may even round it over.

This is one of the most common reasons people say:

“I sharpened it a lot, but it still doesn’t cut.”

Sharpen Forward, Return Without Pressure

Apply pressure mainly during the forward sharpening stroke.

If you scrub aggressively back and forth, the knife tends to move slightly up and down on the stone, making it harder to maintain a consistent angle.

Gradually move along the blade from heel to tip and try to sharpen the entire edge evenly.

The Burr Is Physical Proof That You Reached the Edge

Once you have fully sharpened one side, a thin strip of metal will fold over to the opposite side of the cutting edge.

This is called the burr.

It proves that you have sharpened that side all the way to the apex.

Carefully feel for the burr along the entire blade using the pad of your finger.

Once you can feel it along the full edge, switch sides.

When you have created a burr from both sides, the edge geometry has been formed.

Always Remove the Burr at the End

The burr is extremely thin and fragile.

If left on the knife, it may break off during use, leaving the cutting edge dull or damaged almost immediately.

Finish with very light strokes on your medium or finishing stone, or remove the burr using newspaper or a leather strop.

Careful burr removal makes a major difference to how long the edge stays sharp.

Do Not Wash Away the Sharpening Slurry

The dark slurry that forms during sharpening contains tiny abrasive particles released from the whetstone.

These particles continue to work as an abrasive.

Rather than immediately washing the slurry away, allowing it to remain on the stone can help create a smoother edge.

3. Best Whetstones for Outdoor Knives | How to Choose Your Sharpening Tools

The basic recommendation for an outdoor knife is a #1000 medium-grit whetstone.

However, powder steels such as S30V and M390 often benefit significantly from diamond abrasives. We will explain why in Section 5.

For your first stone, choose a #1000 medium-grit whetstone.

The same #1000 stone you use for kitchen knives can usually be used for outdoor knives.

If your knife is chipped, add a coarse stone.

If you want a smoother finish, add a finishing stone.

For field use or very wear-resistant steels, a diamond sharpener is practical.

4. How to Sharpen Each Blade Grind

① Scandi Grind — Mora Knives and Similar Outdoor Knives

There is a reason Scandi grinds are so beginner-friendly.

The large bevel itself determines the sharpening angle.

Simply place the entire bevel flat against the stone, and you do not need to create or memorize a sharpening angle.

Because the large flat surface contacts the stone, it is also easier to stabilize the blade.

Place the bevel completely flat against the stone and sharpen approximately 20 strokes from heel to tip using light pressure.

When sharpening the curved tip, slightly raise the handle so the entire edge continues to contact the stone.

A common mistake is lifting the knife and creating a secondary bevel.

Doing this creates a shoulder on the original broad bevel, thickening the edge and reducing how well the knife bites into material.

For a Scandi grind, remember:

Do not raise the blade. Keep the bevel flat.

② V-Edge — Common Secondary-Bevel Knives

Many commercially available knives have a small secondary bevel at the cutting edge.

Instead of sharpening the entire blade face, you only need to sharpen the small bevel responsible for the cutting edge.

This makes maintenance much easier.

A general guideline is approximately 10–15° per side.

However, maintaining this angle consistently can be difficult for beginners.

A very useful technique is to colour the bevel with a permanent marker before sharpening.

As you sharpen, the ink disappears only where the stone makes contact.

If the angle is correct, the marker will be removed evenly.

If the angle is too high or too low, ink will remain on part of the bevel.

This gives you immediate visual feedback.

Sharpen both sides, create a burr, then finish by carefully removing it.

③ Convex Grind

A convex grind has a gently curved cutting profile.

Its advantage is that it combines edge strength with good cutting performance.

There is a clear reason why you should avoid aggressively sharpening this geometry on a completely flat whetstone.

A flat abrasive surface can gradually flatten the curved profile, changing the original blade geometry and potentially making the edge thicker and less efficient.

Instead, use a leather strop, or place wet-and-dry sandpaper over a slightly compressible surface such as a mouse pad.

The soft backing allows the abrasive to conform slightly to the curved edge.

Convex sharpening requires more skill.

If you own an expensive knife or are unsure about maintaining the geometry, professional maintenance from the retailer or a sharpening specialist can be a sensible option.

5. Knife Steels and Which Whetstone to Use

This is one of the biggest differences between outdoor knives and ordinary kitchen knives.

Outdoor and EDC knives sometimes use steels designed for exceptional hardness and wear resistance, including powder metallurgy steels and steels containing large quantities of vanadium carbides.

Why?

And why does that change which sharpening stone you should use?

This is where things get especially interesting from a whetstone specialist’s perspective.

Why Outdoor Knives Use Harder Steels

Many ordinary household kitchen knives are around HRC 56–58.

They are used against cutting boards every day, so resistance to chipping and ease of sharpening are important.

Outdoor knives face different demands.

They may be used on rope, wood, cardboard, branches, and other highly abrasive materials, often far away from your sharpening equipment.

Manufacturers therefore increase wear resistance and edge retention by raising hardness to around HRC 59–61 or higher, or by using powder metallurgy steels containing very hard carbides.

However, increasing hardness may reduce toughness and increase the risk of chipping.

Steel selection is therefore always a balance between:

Edge retention ↔ Toughness

Common Knife Steels — Three Main Levels

Entry-Level Steels — AUS-8, 440C, 8Cr13MoV, etc.

Affordable and relatively easy to sharpen.

Edge retention is moderate, but these steels are excellent for beginners and sharpening practice.

A regular household #1000 whetstone works very well.

Mid-Range Steels — VG10, 14C28N, ATS-34, etc.

These steels offer a good balance between edge retention, corrosion resistance, and ease of sharpening.

VG10 is a particularly common Japanese stainless steel and is relatively easy to maintain.

High-End / Powder Steels — CPM-S30V, M390, ZDP-189, MagnaCut, D2, etc.

These steels hold an edge for a long time but are generally harder and more time-consuming to sharpen.

ZDP-189 can reach approximately HRC 64–66 and provides outstanding hardness, but sharpening can be challenging.

MagnaCut has become popular in recent years because it offers an excellent balance of corrosion resistance, edge retention, and toughness.

Carbon Steel

Carbon steels are often easy to sharpen and can take an excellent edge, but they rust more easily.

Drying and oiling after use are essential.

★ The Key Point: High-Vanadium Powder Steels Require the Right Abrasive

The problem is not simply that these steels are “hard.”

If the carbides inside the steel are harder than the abrasive particles in the sharpening stone, an ordinary whetstone may struggle to properly abrade those carbides.

Approximate hardness values illustrate the problem:

This means steels such as S90V, M390, and S30V, which contain significant amounts of very hard carbides, can be more difficult to sharpen effectively with conventional alumina-based abrasives.

At coarse grits—around #400 or below—the surrounding steel matrix may still be removed effectively.

But at finer finishing grits, the abrasive may struggle to cleanly cut the hardest carbides.

Instead, the surrounding material can be removed while harder carbides remain unsupported.

For this reason, diamond and CBN abrasives are particularly effective for high-carbide powder steels.

In practical terms:

First, identify your knife steel.

• Entry-level stainless steels to VG10 → a regular #1000 whetstone is usually sufficient

• High-vanadium / powder steels such as S30V and M390 → diamond or CBN is highly recommended

• Very hard steels are more prone to chipping, so repair chips first with a coarse stone or coarse diamond plate

Outdoor Knives Do Not Necessarily Need a Mirror-Polished Edge

For outdoor tasks such as cutting rope, branches, or making feather sticks, a slightly coarser edge with good “bite” can be more practical than a highly polished mirror edge.

A blade finished around #1000, with the burr properly removed, can be extremely effective in real-world outdoor use.

You do not always need to progress to very fine polishing stones.

Knife Steel and Sharpening Trends

Micro-Bevels for Hard, Chip-Prone Steels

Adding a very small secondary bevel at a slightly steeper angle can strengthen the very apex while maintaining most of the knife’s cutting ability.

This is a useful technique for high-hardness steels.

MagnaCut

MagnaCut has become extremely popular in recent years because it offers a strong balance of corrosion resistance, edge retention, toughness, and relatively manageable sharpening.

Higher-wear-resistance variants can provide greater edge retention but naturally take longer to sharpen.

Damascus Is Primarily a Pattern

The familiar wave pattern of Damascus steel comes from layering different steels and revealing the pattern through processes such as acid etching.

The actual cutting performance is mainly determined by the core steel and heat treatment.

A Damascus pattern does not automatically mean that a knife will perform better.

6. Rust Prevention and Everyday Maintenance

Even a perfectly sharpened knife will lose performance if corrosion attacks the cutting edge.

The main causes of rust on outdoor knives are:

• Water

• Salt

• Tree sap

• Fruit juices

• Plant residue

If these remain on the blade, localized corrosion can develop.

Because the cutting edge is the thinnest part of the knife, corrosion can eventually damage or break away the apex itself.

Putting a wet knife directly back into a leather sheath can make things worse because leather can retain moisture.

Rust prevention essentially comes down to three rules:

Do not leave it wet. Do not leave contaminants on the blade. Dry it thoroughly.

Immediately After Use

Wipe away sap, water, salt, and other residue.

Dry the knife thoroughly.

This alone prevents a large proportion of rust problems.

Rust Protection

Apply a very thin layer of knife oil, such as camellia oil, to the blade and moving parts.

Do not store a wet knife inside its sheath for long periods, especially a leather sheath.

Carbon Steel

Some carbon-steel knife users intentionally develop a dark protective patina on the blade.

This can help reduce the formation of more damaging red rust.

Carbon steel is a material that develops character as it is used and maintained.

Light Surface Rust

Remove minor rust using an appropriate rust-removal method or metal polish before sharpening.

Avoid simply sharpening directly over active corrosion.

7. Emergency Sharpening in the Field

If your knife becomes dull while camping or outdoors, a portable diamond sharpener is extremely useful because it requires no water.

In an emergency, the unglazed ceramic ring on the bottom of a mug can also be used to temporarily touch up an edge.

However, these are temporary solutions.

Once you return home, properly sharpen the knife on a whetstone and remove the burr.

８. What Not to Do

Frequently Asked Questions

Q. What angle should I use to sharpen an outdoor knife?

For a V-edge with a secondary bevel, approximately 10–15° per side is a useful guideline.

For a Scandi grind such as those found on many Mora knives, place the entire bevel flat against the whetstone.

You do not need to manually determine the angle.

The most important point is not the exact number of degrees—it is maintaining the same angle throughout the entire sharpening process.

Q. Which sharpening stone should I buy first? Do I need diamond?

Start with one #1000 medium-grit whetstone.

The same stone can usually be used for your kitchen knives.

If the knife has chips, add approximately a #400 coarse stone.

For emergency field sharpening, a portable diamond sharpener is useful.

For powder metallurgy and high-vanadium steels such as S30V and M390, diamond or CBN abrasives are particularly effective because conventional stones may struggle at finer grits.

Q. Is a diamond sharpener enough?

Diamond sharpeners are excellent for:

• Maintaining everyday sharpness

• Sharpening wear-resistant steels

• Outdoor use where water is unavailable

However, traditional whetstones can provide a smoother and more controlled finish.

Affordable electroplated diamond sharpeners also tend to be relatively coarse.

A practical approach is:

Outdoor use / hard steels → Diamond

Controlled sharpening and refined finishing → Whetstone

Q. Can I sharpen a knife with a cheap whetstone or pull-through sharpener?

Yes, they can work for basic sharpening or emergency maintenance.

However, inexpensive stones often wear unevenly and may have less consistent grit.

A good #1000 whetstone provides much better control and consistency.

Pull-through sharpeners can restore a usable edge quickly, but if you care about preserving blade geometry and maximizing the life of the knife, sharpening with a whetstone is generally the better option.

Choosing the Right Whetstone

For most outdoor knives, a #1000 medium-grit whetstone is the best place to start.

From there, choose additional stones depending on your needs:

• Around #400 for chip repair and reshaping

• Around #1000 for everyday sharpening

• #3000 and above for a smoother finish

• Diamond abrasives for high-wear-resistance powder steels

• A leather strop for burr removal and convex edges

The most important thing is not owning many sharpening stones.

It is understanding your blade geometry, steel, and intended use, then choosing the abrasive that matches them.