Mule D2 Tool Steel Original Filipino Balisong butterfly Knife BF-87

The BF-87 Mule is a 24cm balisong with a 12cm D2 blade at 190g. The handle carries brass, stainless and kamagong on one frame, which is three materials where most knives use two. The name is not an accident.

Why mix brass and stainless on the same handle

Because they do different jobs and there is no rule saying you have to pick one.

Brass is dense, warms in the hand almost immediately, and develops a brown patina that maps how you hold the knife. Stainless is lighter for its volume, stays exactly the colour it arrived, and shrugs off everything. On most knives you choose. Here you get both, and the weight lands at 190g, which is between our 180g brass knives and where an all-stainless build would sit.

The interesting consequence is that this knife ages unevenly on purpose. In two years the brass will be brown, the stainless will be bright, and the contrast between them will be sharper than it is today. Some people find that untidy. We think it is the best thing about it.

One hundred and ninety grams

An odd number and a useful one. Our 24cm knives mostly sit at 175g or 180g. Ten to fifteen grams sounds like nothing and is genuinely noticeable, because it comes off the handle rather than the blade and it changes how long a rotation takes.

What you get is a knife that carries through a rollover with a little more certainty than a 180g knife, without stepping up to the 250g class where a long session becomes a forearm workout. If you have flipped a 180g balisong and wished for slightly more, this is that knife.

The name, which for once is apt

A mule is a hybrid, it is unglamorous, and it is famously the most useful animal on the farm. Three materials, an odd weight, no obvious showpiece feature, and it will outwork most of what is on this page.

We are not going to pretend the animal series was carefully assigned. This one landed well by accident and we are taking the credit anyway.

D2 steel on a balisong, and who it suits

D2 is an air-hardening tool steel: roughly one and a half percent carbon and eleven to twelve percent chromium. Chromium at that level sits just below the stainless threshold, so it resists corrosion well without being immune, which is why the trade calls it semi-stainless.

It holds an edge longer than anything else we sell. In exchange it is stubborn to sharpen and wants a diamond plate, because the carbides that give it wear resistance are harder than the abrasive in a common ceramic stone.

The honest split: buy D2 if you want to sharpen a knife twice a year and otherwise leave it alone. Buy our high carbon knives if sharpening is something you actively enjoy. Neither is the premium option.

We run it at 58-60 HRC. Harder holds longer and chips when it meets a floor, and a balisong meets a floor.

Living with a kamagong balisong handle

Philippine ebony, dense, close-grained, near black. It needs no oil and no care, it will not crack or shrink, and it will take a soft polish where your hand sits. It is the one material on this handle with nothing to say for itself, which on a knife this busy is welcome.

Ordering this D2 balisong

Unsharpened trainer, selected above Add to Cart. Same three materials, same 190g, same balance, no edge, and the same price because grinding an edge is one operation in a long build.

A fitted leather sheath is in the box. US shipping is free, everywhere else a flat $49 for the whole order regardless of size.