The basic layout
A balisong uses two handles that rotate around pivots at the blade tang. On a sharpened balisong, the bite handle is the handle that closes over the cutting edge; the other is commonly called the safe handle. Trainers replace the sharpened blade with a blunt training blade while preserving the two-handle mechanism.
Pivots and hardware
The pivot area determines how each handle swings. Common systems use washers, bushings, bearings, or combinations of precision hardware. Bushings are fitted around the pivot and can allow a properly tuned knife to swing freely while controlling side-to-side play. Bearings reduce sliding friction with rolling elements. Washer-only systems are mechanically simpler and depend heavily on fit and adjustment.
Zen pins and tang pins
These parts define where the handles stop in the open and closed positions. Zen pins are located in the handle/frame area and contact the blade tang. Tang pins are located on the blade tang and contact the handles.
Handle construction
Channel handles are formed as a channel-shaped piece. Sandwich construction uses separate handle slabs or liners joined by hardware and spacers. Some modern designs blend ideas from both approaches. Material, handle geometry, end weight and spacers all affect grip and balance.
Blade and trainer blade
Live blades vary by profile, grind, steel and edge geometry. Trainer blades are intentionally unsharpened. A trainer can reduce cutting risk during practice, but the moving handles and hard surfaces can still cause injury.