Knife Edge Geometry and Grind Types: A B2B Buyer Guide to Flat, Hollow, Scandi, Convex & Sabre Grinds for Outdoor Knives

Most B2B knife buyers spend 80% of their sourcing time discussing steel, handle, and lock type. Then the factory ships a sample with the wrong grind geometry, and the buyer discovers that the cross-section of the blade — not the steel on the data sheet — is what actually determines slicing ability, edge durability, sharpening feel, and end-user satisfaction.

In this guide, we break down the six knife edge geometry and grind types that matter for outdoor knife sourcing, explain how each one performs in the field, and show what B2B buyers and OEM brand owners should put on the spec sheet before signing a purchase order.

## Market Context: Why Grind Geometry Is the New Differentiator

According to Verified Market Reports (April 2026), the global outdoor knife market reached USD 1.25 billion in 2025 and is projected to grow to USD 1.90 billion by 2032 at a 6.18% CAGR. Folding knives accounted for 56.7% of unit share, with camping and hiking representing 42.8% of end-use. North America led at 39.81% revenue share.

In that environment, steel and lock type are increasingly table stakes. The leading brands differentiate through edge geometry — the cross-sectional shape of the blade from spine to edge. As we noted in our Knife Blade Coatings and Finishes guide, geometry interacts with surface treatment to shape how the blade cuts, how it sharpens, and how it feels. Two knives in identical 440C steel can perform like completely different products if one is full-flat ground and the other is sabre ground.

For B2B buyers building a private-label line, getting the grind specification right is the single highest-leverage decision in the OEM process.

## What Is Knife Edge Geometry?

Knife edge geometry is the cross-sectional shape of a blade from spine to cutting edge. It is built from two parts: the primary grind (the main taper from spine toward the edge) and the secondary bevel (the small final angle that actually does the cutting). A Scandi grind uses only a primary bevel, a hollow grind has a concave primary that meets a small secondary edge, and a sabre grind stops its flat primary partway up the blade, leaving the upper portion at full thickness for strength.

The grind type controls four performance variables: slicing efficiency, edge durability, sharpening difficulty, and material release. It also drives material cost, grinding time, and per-unit MOQ in OEM production.

## The 6 Main Knife Edge Geometry and Grind Types

### 1. Full Flat Grind

The full flat grind runs from the spine all the way to the edge in a single straight taper. It is the default geometry on most EDC folders, kitchen knives, and many hunting fixed blades.

Performance profile: Thinnest cross-section behind the edge, lowest cutting resistance, excellent food release, easy to sharpen on a whetstone.

Best for: EDC, kitchen prep, hunting skinning, any push-cut task where clean slicing matters more than impact strength.

B2B note: Full flat ground blades are the simplest specification to source. They grind fast, run on standard CNC belt lines, and yield the lowest defect rate at the OEM stage. For first-time private-label buyers, flat grind is the lowest-risk default.

### 2. Hollow Grind

A hollow grind has concave bevels on each side of the blade that meet at the edge. The result is a thin, crescent-shaped cross-section at the very tip.

Performance profile: Extremely thin edge geometry, very aggressive initial sharpness, but the thin edge is more prone to chipping on hard or dirty material. Excellent for slicing soft material and detail work.

Best for: Skinning knives, traditional pocket knives, razors, and outdoor knives where the buyer is willing to trade durability for razor sharpness.

B2B note: Hollow grinding requires specific wheel-shaped contact wheels that not every factory maintains. Confirm the supplier’s hollow-grind capability before placing a large order, and request a small batch run first.

### 3. Scandi (Scandinavian) Grind

The Scandi grind features a single wide primary bevel that runs from roughly the middle of the blade down to the edge with no secondary bevel.

Performance profile: Strong edge support for carving, feather sticking, and bushcraft tasks. The wide, flat bevel acts as a built-in sharpening guide in the field, which is why it dominates the Scandinavian outdoor market. Trade-off: reduced slicing efficiency on flat or hollow-ground tasks.

Best for: Bushcraft, carving, camp chores, and any use case where end users will resharpen their own knife in the field with a simple stone.

B2B note: Scandi grind is the European market’s preferred geometry for bushcraft and outdoor survival segments. If your distribution channels include Germany, Scandinavia, or the UK outdoor market, including a Scandi option in the line is a strong differentiator.

### 4. Convex (Hamaguri) Grind

A convex grind curves outward from the spine to the edge, leaving more metal behind the bevel than any flat or hollow style. In Japanese knifemaking it is known as the Hamaguri (clam-shell) grind.

Performance profile: Highest edge durability and longest edge retention of all common grinds. The thick geometry resists chipping and is self-supporting under heavy impact. Trade-off: more difficult to sharpen consistently, requires convex sharpening tools or experienced freehand technique.

Best for: Chopping, batoning, heavy bushcraft, axes, machetes, and any outdoor knife that will see impact loads.

B2B note: Convex grinds are typically produced by slack-belt grinding or progressive wheel contact, which adds time per unit. Expect slightly higher per-piece cost and confirm the factory’s convex capability before scaling.

### 5. Sabre (Saber) Grind

The sabre grind is a partial flat grind that begins partway up the blade rather than at the spine. The upper portion of the blade stays at full thickness, adding strength behind the edge.

Performance profile: A balanced geometry — better edge durability than full flat, better slicing than a true convex. The dominant geometry on tactical, military, and survival knives.

Best for: Tactical folders, military and law-enforcement fixed blades, survival knives, and any product positioned as “hard-use.”

B2B note: Sabre grind is the most common geometry on Chinese OEM tactical and fixed-blade lines, which means short lead times, low cost, and predictable quality from most Yangjiang suppliers.

### 6. Chisel (Single-Bevel) Grind

A chisel grind is ground on only one side of the blade, with the other side flat. The single bevel produces an extremely acute edge angle.

Performance profile: Very fine cutting, very thin edge. Common on Japanese kitchen knives, woodworking tools, and specialty outdoor cutting tools. Trade-off: pulls slightly to one side during cuts, requires specific sharpening tools.

Best for: Japanese-style kitchen knives, sushi and sashimi applications, precision woodworking, and specialty outdoor use.

B2B note: Chisel grind is a niche geometry for the outdoor market. It is more relevant if your product line also crosses into kitchen or specialty cutlery.

## Grind Selection by Application

If you are building a multi-SKU product line, include one full-flat, one sabre, and one Scandi grind as the core trio. That covers the major outdoor segments without overcomplicating the SKU matrix.

## B2B OEM Specification: 7 Parameters to Lock Down

When sourcing edge geometry from a Chinese OEM, your specification sheet should include the following seven parameters for each SKU:

1. Primary grind type (flat, hollow, sabre, Scandi, convex, chisel)
2. Primary bevel angle per side (typically 8°–15° per side for outdoor knives)
3. Secondary bevel angle per side (typically 15°–25° per side; specify if you want zero-grind / Scandi with no secondary)
4. Edge thickness behind the secondary bevel (target value in mm; lower = better slicing, higher = more durable)
5. Spine thickness (drives overall blade stiffness)
6. Grind symmetry tolerance (typically ±0.2 mm per side for premium lines)
7. Surface finish after grinding (satin, mirror, or pre-coated — drives the next step in production)

These seven parameters determine the cutting feel of the final product. If you leave any of them open, the factory will default to the lowest-cost option, which may not match your target market.

## Cost, MOQ, and Lead-Time Impact

Grind geometry directly affects OEM cost in three ways:

• Grinding time: Convex and Scandi grinds take 30%–60% longer per blade than full flat grinds, because they require multiple progressive belt or wheel passes.
• Tooling and wheel wear: Hollow grinds require specific contact wheels. Convex grinds require slack belts or progressive wheel systems. Factories without the right tooling will quote higher per-piece costs.
• Skill and defect rate: Full flat is the easiest geometry to inspect and control. Convex and hollow require experienced operators and have higher defect rates at first article.

For most Yangjiang OEM factories, the MOQ tier remains the same across grind types (typically 500–1,000 units per SKU), but the unit cost differential is real. Plan a 5%–15% cost premium for convex, Scandi, or specialty grinds compared to standard full flat.

## Compliance Notes

Edge geometry interacts with compliance: EU REACH restricts some steel alloys and coatings (geometry itself is not restricted); US states like California, New York, and New Jersey cap carry blade length; UK and EU folding rules apply to locking knives, so a non-locking slip-joint geometry avoids UK carry restrictions. For multi-region private-label buyers, the safest design is a single geometry paired with a folding or fixed configuration sellable compliantly in the largest markets.

## Common B2B Mistakes to Avoid

1. Specifying only the steel and skipping the grind. A premium steel in the wrong grind still cuts poorly.
2. Assuming full flat is always the best default. Not the right answer for bushcraft or impact-heavy segments.
3. No first-article inspection on grind geometry. A 0.5 mm variation in edge thickness can change the cutting feel of the entire run.
4. Ignoring secondary bevel angle. The primary grind controls strength, the secondary bevel controls cutting. Both need to be specified.
5. Sourcing Scandi or convex from a factory that does not specialize in them. Specifying outside the factory’s default geometry raises cost and risk.

## Why Ruihalo for OEM Edge Geometry

Ruihalo is a Yangjiang-based outdoor knife and tool manufacturer with full in-house capability across all six grind types — full flat, hollow, sabre, Scandi, convex, and chisel. Our OEM/ODM service supports custom grind specifications per SKU, with a typical MOQ of 500–1,000 units and a 30–45 day lead time. Every first article is measured against the seven-parameter spec sheet before mass production begins.

For buyers building a private-label line, the right starting point is a short conversation about target market, retail price point, and end-user task. From there we recommend the optimal grind geometry and submit first-article samples for your in-hand testing.

Explore our outdoor knives product range and submit your OEM inquiry here or request a quote to start your spec sheet.

## Frequently Asked Questions

What is the best knife grind for everyday carry?
Full flat grind is the best all-around choice for EDC because it slices efficiently, sharpens easily, and is the lowest-cost geometry to produce at scale. A sabre grind is a strong second if the target user prioritizes durability over slicing.

What is the difference between a flat grind and a sabre grind?
A flat grind tapers from the spine all the way to the edge. A sabre grind starts its taper partway down the blade, leaving the upper section at full thickness. Sabre is stronger behind the edge, flat grinds slice more cleanly.

Why do bushcraft knives use a Scandi grind?
The Scandi grind has a single wide primary bevel with no secondary bevel, which acts as a built-in sharpening guide. Users can resharpen in the field with a single stone, and the geometry provides strong edge support for carving and camp tasks.

Does grind type affect knife cost?
Yes. Full flat grind is the cheapest geometry to produce at scale. Scandi, convex, and hollow grinds require additional grinding time, specific tooling, and more skilled operators. Expect 5%–15% higher per-unit cost for specialty grinds.

Can one factory grind all six main types?
Not always. Full flat and sabre are the most common. Hollow, Scandi, and especially convex require specific equipment and operator skill. Always confirm a factory’s proven capability in your target grind before placing a production order.

## Related Articles

• Knife Steel Comparison: VG10 vs AUS-10 vs 440C
• Knife Handle Materials: The Complete B2B Sourcing Guide for 2026
• Knife Blade Coatings and Finishes: A B2B Buyer Guide
• Folding Knife Locking Mechanisms: A B2B Buyer’s Guide
• Carbon Steel vs Stainless Steel Outdoor Knives
• How to Verify a China Knife Manufacturer