What Is a Butterfly Knife? Balisong Anatomy and Safety Basics

A butterfly knife — also called a balisong — is a type of folding pocketknife that originated in the Philippines. Its defining feature is two handles that counter-rotate around the tang of the blade, so that when the knife is closed, the blade is concealed within grooves in the handles. A latch, typically mounted on the handle that closes against the cutting edge, holds the knife shut.

Why Is It Called a Butterfly Knife?

The name balisong comes from Barangay Balisong in Taal, Batangas province, one of the original manufacturing centers of these knives in the Philippines. A popular folk etymology suggests the word derives from the Tagalog phrase baling sungay, meaning broken horn, because early handles were traditionally carved from carabao or deer horn. Traditional Filipino balisongs are also known as veinte y nueve — Spanish for twenty-nine — because they measure about 29 cm when fully open. The butterfly knife nickname refers to the way the two handles swing around the blade during manipulation.

Anatomy of a Butterfly Knife

Understanding the parts is the fastest way to understand how the knife works:

• Bite handle: the handle that closes on the sharp edge of the blade. It usually carries the latch, and it will cut you if you hold it while the knife closes.
• Safe handle: the handle that closes on the unsharpened spine of the blade.
• Latch: the standard locking system that holds the knife closed. There are Batangas latches (mounted on the bite handle), Manila latches (mounted on the safe handle), and spring latches.
• Tang pins: small pins on the tang that space the handles apart, prevent the blade from hitting the handles, and engage the latch. Some knives use zen pins embedded in the handles instead.
• Swedge: the unsharpened spine of the blade.
• Kicker: the area of the blade that keeps the sharp edge from touching the inside of the handle.

How the Flip Works

Because the handles rotate independently around the blade's tang, a trained user can open the knife one-handed with a continuous motion — and the same motion can be reversed, closed, and manipulated in a series of flourishes. These manipulations, called flipping, are performed for art and amusement as well as for speed. Blunt trainer versions of the knife are widely available and let beginners practice the same movements without risking injury.

Balisongs are built two main ways: sandwich construction, where layered handle slabs are pinned or screwed together with the blade resting between them, and channel construction, where each handle is milled from a single piece of material with a groove for the blade. Channel construction is generally regarded as the stronger of the two. The pivot system can use bearings, bushings, or washers-only, with bushings being the mark of a higher-quality modern knife.

What Is a Butterfly Knife Actually Used For?

Historically, Filipinos in the Tagalog region used the balisong as a pocket utility knife and self-defense tool, and hollow-ground versions were even used as straight razors before conventional razors were widely available. In the modern world, the butterfly knife's practical utility is limited — most EDC tasks are better served by a conventional locking folder — and its reputation is dominated by flipping as a skill sport and by its collector following. If everyday utility is the goal, a standard folding knife is the more practical choice.

Safety and Legal Status

The butterfly knife is illegal, or its blade length is restricted, in several countries. It is often regulated under the same laws as switchblades and gravity knives because of how quickly it can be deployed one-handed. In Australia, for example, balisongs are generally classified as a prohibited weapon, and Belgium and Denmark explicitly ban them. Always check the law in your jurisdiction before buying or carrying one.

A balisong's two counter-rotating handles hide the blade when closed.

If you want to learn flipping, start with a trainer and practice over a soft surface, away from people and pets. A butterfly knife is a precise mechanical instrument — respect the tool, and respect the law.

For a deeper dive, see the full history and mechanics of the balisong and how it fits into knife legislation around the world.

---

Find your ideal everyday carry configuration — explore the Artisan Cutlery folding knife collection for premium EDC folders built for reliable everyday carry.