What Is a Butterfly Knife? Balisong Anatomy, Origin and Uses

Written by Nathaniel, in the workshop. Last checked 26 August 2026.

A butterfly knife is a folding pocket knife with two handles that rotate around separate pivots at the base of the blade, so the blade sits hidden inside the closed handles until you swing them apart. Its other name is balisong, after the Filipino knifemaking tradition in Taal, Batangas, where the design was refined into the form everyone still copies.

That is the short version. The longer version is where most of the internet falls apart.

What makes a butterfly knife different from a normal folder

A normal folder has one handle and one pivot. The blade swings out of a slot, a lockbar catches it, and that is the whole story.

A balisong has two handles and two pivots, and nothing locks the blade until the handles close back together and the latch drops. The blade is not held by a spring. It is held by geometry, by your hand, and by whether the pivots were tuned before the knife left the shop. That last part is why a good one feels like a door on new hinges and a bad one feels like a garden gate.

What are the parts of a butterfly knife?

Learn these eight words and you will understand every balisong review you ever read, including the ones written by people who have never held one.

• Blade. The cutting edge and the point. Ours run 58 to 60 HRC, the window where an edge holds up without turning brittle.
• Tang. The chunk of steel behind the edge that the pivots pass through. The engine room. Every bit of the knife’s action is decided here.
• Tang pins. Small pins sticking out of the tang that stop the handles swinging past and slamming into the edge. Some designs use zen pins in the handles instead. Either works. Having neither does not, and you will hear about it the first time a handle meets the edge.
• Pivots. The two screws or rivets the handles rotate on. Too tight and the knife stalls mid flip, too loose and it rattles like a maraca. Screw pivots you can adjust yourself. Peened pivots you cannot.
• Handles. Two of them. Either channel construction, milled from one piece with a groove for the blade, or sandwich construction, two slabs bolted around spacers. Channel is stronger and heavier. Sandwich is easier to tune and to fit horn or micarta to.
• Latch. The little hook that keeps the knife shut. Some sit on the bite handle, some on the safe handle, and makers have argued about which is correct for a century without resolving it.
• Bite handle. The handle on the same side as the cutting edge. Close the knife carelessly holding this one and it will introduce itself to your fingers. Hence the name.
• Safe handle. The handle on the spine side. This is the one you hold, and the one you should be holding right now if you are reading with a knife in your hand, which some of you are.

Bite handle versus safe handle, in one sentence

The safe handle is on the blade’s spine side and cannot cut you when the knife closes; the bite handle is on the edge side and absolutely can. Every trick you will ever learn is described by which handle you are holding, so this is vocabulary, not trivia.

Why is it called a balisong?

The most repeated explanation is that “balisong” comes from “baling sungay”, Tagalog for “folding horn”, because the earliest handles were carved from carabao horn. That fits the object and the material, and if you have ever cut horn you know it behaves like nothing else on a belt sander.

There is also Barangay Balisong, in Taal. Whether the knife took the name from the place or the place became known for the knife is not something anybody can settle with a document, and we will not pretend otherwise.

The other name you will hear is “veinte y nueve”, Spanish for twenty nine, after the classic 29 centimetre open length. If a seller tells you it means something more mystical than a measurement, they are selling you a story with a knife attached.

Where does the butterfly knife come from?

Taal, in Batangas province, in the Philippines. That is the tradition that produced the balisong as a recognised object, with named makers, family workshops and an industry that still exists. Perfecto de Leon is the name most often credited with popularising the design in the early 1900s, and that is as far as the documented record honestly stretches.

Batangas makers worked with what was in front of them: leaf springs and old files for steel, carabao horn and brass for handles. A workshop solving a supply problem, not folklore.

Who invented the butterfly knife, and when?

Nobody can name the person. That is the honest answer, and every page that hands you a confident name and a precise year is guessing dressed up as history.

The most famous guess is that a French tool catalogue from 1710 shows a “Balisong”, proving a European origin. It does not. Old European pivoting and fan-style folding tools exist, but the 1710 claim traces back to a mistranslated and endlessly reposted reference. It has been copied from blog to blog for twenty years because it sounds like the kind of fact that ought to be true.

What we will say with a straight face: the design was established and produced in Batangas from the early twentieth century, spread worldwide with returning US servicemen after the Second World War, and by the 1980s was common enough in the West to attract legislation.

Butterfly knife myths versus what actually holds up

What are butterfly knives used for?

Three categories, and they barely overlap.

Flipping. This is what most people buy one for now, and there is no shame in it. Flipping is a skill discipline with its own vocabulary and its own competitions. Rollovers, aerials, chaplins. Fidgeting turned into something you can get good at, which is why we offer a trainer version of every model at the same price. Learn on the unsharpened one.

Cutting things. A balisong is a knife. It opens rope, boxes and packaging as well as any folder in the same steel, and faster than most, because a practised one hand opening beats hunting for a thumb stud. That is what they were for in Batangas and it is still what they do.

Collecting. Steel, handle material, pattern, maker. Two knives with stag horn handles are never identical, because the horn never was, and for a certain kind of buyer that is the entire point.

Are butterfly knives legal?

It depends on where you live, and you need to check before you buy. In the United States the rules are set state by state, and some cities add their own. Outside the US, several countries restrict or ban them outright.

Most “knife law” pages online are copied from older articles and were never updated when the law changed. Read the statute for your own state or country, or ask a local attorney. We keep a state by state breakdown at butterfly knife laws by state. Where a live blade is restricted a trainer is often permitted, but not everywhere, so verify it.

Which one should you start with?

Every knife we ship goes out with a fitted leather sheath, and every model has a trainer twin at the same price. Free US shipping, flat $49 worldwide. Our 650 approved reviews average 4.79 out of 5, which we mention only because the alternative is asking you to take our word for it.

Butterfly knife questions we actually get asked

Is a butterfly knife the same thing as a balisong?

Yes. Balisong is the Filipino name, butterfly knife the descriptive English one, and both mean the same knife. Flippers say balisong. Search engines say butterfly knife.

Why is it called a butterfly knife?

Because of how it opens. The two handles swing out and around like wings, and when the person doing it knows what they are doing, it genuinely looks like that.

When were butterfly knives invented?

The balisong as a standardised, produced object dates to Batangas in the early 1900s. Earlier pivoting folding tools existed elsewhere, but no verified record ties them to this design or fixes an invention date.

Who invented the butterfly knife?

No single person can be named. Perfecto de Leon is credited with popularising the design in Taal in the early 1900s, which is the closest thing to an answer that survives scrutiny.

What does “veinte y nueve” mean?

Twenty nine, in Spanish, for the traditional 29 centimetre open length. A measurement, nothing more.

What is the difference between a trainer and a live blade?

The trainer has no cutting edge. Same weight, same pivots, same handles, so muscle memory transfers directly. Learn the trick on the trainer, then do it on the live one.

How do I tell a good balisong from a cheap one?

A named steel grade, tang pins or zen pins present, pivots that hold tension after a hundred flips, handles that meet flush when closed. If a listing will not name the steel, that is your answer.

Pick the steel you want and take the trainer with it. Start here if you would rather look than read.