MK: DIY Butterfly Knife

Knife again! This time it´s butterfly knife, or balisong.

Materials: saw blade for blade, mild steel for handles, 2X M3, 4XM2,5 nuts&bolts, steel tube inner ⌀3mm.

Tools: angle grinder, drill press, belt sander, bench grinder, file, hack saw.

Step 1: Blade

I started by cutting the rough shape from the old saw blade using the angle grinder with cut off wheel. Then I shaped the steel with angle grinder with grinding wheel. Later I created a bevel first roughly with angle grinder, than finely with small belt sander. I painted parts of the blade I wanted to grind with a sharpie, so I would have better control over what I should grind.

Then I tried to drill the holes in the handle, first with regular HSS drill bits, but I haven´t had much succes with them, so I switched to sharpened masonry drill bit. I learned this trick from John Heisz.

Step 2: Handles

I had little wider piece of steel than I needed to start with so I cut it to thin strip with an angle grinder. Then I drilled holes for the screws and countersunk them. After this I rounded over the front face of the handle using the bench grinder, dipping the workpiece in water to keep it nice & cold.

Step 3: Latch

I made the latch from round mild steel stock by first filling the flat sides, then drilling the hole and lastly cutting it off with the hack saw

Step 4: Nuts & Bolts

1-first handle

2-second handle

3-blade

4-tube

5-bolt

6-nut

In this assembly the metal tube works as a bearing for the blade. The tube is slightly thicker than the blade, therefore when tho bolt is tightened, the blade is not squeezed, but can rotate freely around the tube. The nut is pressed in the handle. It would be easier to just tap the handle, but unfortunately, I don´t have tap of this size.

Step 5: Afterthoughts

I really like the style and functuality of this knife, however I should´ve spent bit more time on sanding and finishing. Please let me know what you think about it and check out my YouTube channel for more projects like this one!