Scissor Blade Types Explained: Convex, Flat, and Bevel Edges
The shape of a scissor blade — specifically its cross-section and how the cutting edge is ground — affects everything from cutting feel to technique suitability. Understanding blade types helps you choose a scissor that matches how you work, and helps you communicate accurately with your sharpener.
The Three Main Blade Cross-Sections
Convex Edge (Hamaguri / Clam-Shell)
The convex edge is ground so the blade face curves outward toward the cutting edge, producing a gently rounded cross-section.
How it cuts: The rounded geometry reduces the surface area in contact with the hair, allowing the blades to glide through cleanly with minimal resistance. The result is a smooth, almost effortless cutting sensation.
Best for: General salon cutting, wet cutting, dry cutting, and most standard techniques. The convex edge is the most versatile professional blade type and is used in the majority of high-quality Japanese scissors.
Sharpening: Requires a skilled sharpener with hollow-ground equipment. More involved to maintain than a flat-ground edge, but the results are worth it.
All Mina Shears and Ichiro Shears models use convex edge blades.
Flat Edge (Sasa Blade / Flat Ground)
The flat edge is ground with a flat face on one blade side. The cutting edge is still sharp, but the geometry differs significantly from convex.
How it cuts: The flat geometry creates more surface contact and a slightly different resistance profile. The blade doesn’t glide as freely, but this characteristic is actually an advantage for slide cutting — the blade grips the hair just enough to control the slide motion.
Best for: Slide cutting (also called stroke cutting or slithering). Stylists who specialise in textured, graduated, or softly blended finishes often prefer a flat-ground blade for this technique.
Sharpening: Relatively straightforward — the flat face is easier to sharpen consistently than a convex edge.
The Ichiro Slide model uses a flat edge specifically optimised for slide cutting.
Bevel Edge (Semi-Convex / Traditional)
The bevel edge is a traditional design with a visible grinding bevel on one face of the blade. It sits between convex and fully flat in terms of geometry.
How it cuts: More cutting power and durability than convex. The edge resists chipping better and holds up well to thicker hair or repeated use. Cutting feel is more deliberate than convex.
Best for: Barber scissors, heavy-use cutting, or stylists who prefer more tactile feedback when cutting. Also common in entry-level scissors.
Sharpening: The most straightforward of the three types to sharpen, and accessible to a wider range of sharpeners.
Blade Orientation: Inside vs. Outside Edge
On a convex scissor, each blade has one flat face and one convex face. The convex face faces outward (away from the hair) and the flat face faces inward (toward the opposite blade). This geometry is what enables the two blades to pass each other cleanly without catching.
If you are buying left-handed scissors, make sure the blade geometry is correct for left-hand use — it’s not simply a mirror image, it requires the blade to be ground for the opposite hand.
Thinning Scissor Blade Types
Thinning and texturising scissors use a serrated blade on one side, which determines how much hair is removed per snip (the removal rate) and the blending pattern.
- Standard serrated (25–30% removal): Natural blending, suitable for most thinning tasks
- Fine-tooth serrated (15–25% removal): Lighter, more controlled blending — less risk of visible cut lines
- Wide-tooth or chunky (30–45% removal): Heavier texture and volume removal; used for strong definition or point cutting effects
Choosing Based on Your Technique
If you predominantly cut hair using:
- Standard salon cutting (wet or dry): Convex edge
- Slide / stroke cutting: Flat edge
- Barber / clipper-over-comb: Bevel or convex
- Heavy volume removal / texturising: Thinning scissors with appropriate tooth count
Matching your blade type to your primary technique will improve your results and reduce hand fatigue.