Convex vs Bevelled Edge Scissors: A Hairdresser's Guide

The edge type on your hairdressing scissors determines how the blade interacts with hair. Convex and bevelled are the two main edge profiles, and each works fundamentally differently. Understanding the distinction helps you choose the right tool for your cutting style and maintain it properly.

How a Convex Edge Works

A convex edge (also called a hamaguri edge or clamshell edge) has a smooth, curved blade profile. If you looked at the blade cross-section under magnification, you would see a gentle curve from the spine of the blade to the cutting edge, similar to the shape of a Japanese katana. The edge is ground to an extremely fine angle, typically between 40 and 50 degrees.

This geometry allows the blade to slice through hair with minimal resistance. The hair passes along the curved surface and is cut cleanly at the finest point. There is almost no pushing or folding of the hair — it simply parts at the edge.

How a Bevelled Edge Works

A bevelled edge has a V-shaped profile. The blade has a flat surface that meets the cutting edge at a defined angle, typically between 30 and 45 degrees. If you looked at the cross-section, you would see a clear angular change where the bevel begins — like the edge on a kitchen knife or chisel.

Bevelled edges cut by trapping hair between the two angled surfaces and shearing it. This works well for straight, clean cuts but creates more resistance when you try to slide the blade through hair.

Sharpness and Edge Retention

A convex edge can be ground to a finer point than a bevelled edge, which means it achieves a sharper initial cutting edge. However, the finer the edge, the more delicate it becomes. Convex edges require premium, hard steel (58+ HRC) to maintain that fine geometry without chipping or rolling.

A bevelled edge is less sharp at its finest point but is structurally more robust. It can be made from softer steels without losing its functional geometry as quickly. This is one reason why budget scissors almost always use bevelled edges — the steel they are made from cannot support a convex profile.

Which Techniques Suit Which Edge?

Convex Edge Excels At:

• Slide cutting: The curved profile glides through hair effortlessly
• Point cutting: Precision tip work with minimal hair disturbance
• Texturising: Clean, precise removal of individual strands
• Wet cutting: Slices through wet hair without pushing it
• Any technique requiring effortless slicing motion

Bevelled Edge Excels At:

• Blunt cutting: Clean, straight lines on dry hair
• Club cutting: Simple, direct cuts through sections
• Training scissors: More forgiving of technique errors
• High-volume basic cutting: Where speed matters more than finesse

Maintenance Differences

Convex edges require specialised sharpening. The curved profile must be restored on a flat hone or specialised wet grinding wheel by someone trained in convex edge geometry. Using a standard sharpening stone or pull-through sharpener on a convex edge will destroy the curved profile, converting it to a rough bevelled edge that cannot easily be restored.

Bevelled edges are simpler to sharpen. The flat bevel can be restored with more basic equipment, which is why sharpening costs tend to be lower for bevelled scissors.

This sharpening difference is important: always use a professional sharpening service that specifically handles convex-edge scissors. Our mobile sharpening service specialises in convex-edge Japanese scissors.

What ShearGenius Uses

Every ShearGenius scissor uses a convex edge. We pair this edge geometry with Japanese Hitachi ATS-314 steel at 58-62 HRC — hard enough to support the fine convex profile and maintain it for 600-800+ haircuts between sharpenings.

The combination of premium steel and convex edge geometry is what gives ShearGenius scissors their effortless cutting feel. The blade does the work so your hands do not have to.

The Bottom Line

For professional hairdressers using modern cutting techniques, a convex edge is the clear choice. It delivers superior sharpness, smoother cutting action, and better results across the widest range of techniques. The only trade-off is that it requires professional sharpening and premium steel — both of which are worthwhile investments in your craft.

Browse our cutting scissors range to experience the difference a convex edge makes.