I picked up a pair of stainless steel Piranha’s from Fish Bone Knotless Gear during their Kickstarter campaign several months ago. Since then, I’ve been trying to find a way to use it with my hammock gear and tarps. Fish Bone promotes this hardware device as a no-knot solution to hanging line, including tarps or clotheslines. I like to tinker with hardware devices to see if they deliver on any promise of improved speed, efficiency, take-down, or dexterity—functions more critical in winter when gloved hands make working with knots more difficult. When I wrote my post on knots verses hardware, I had only just received the Piranhas and it prompted me to analyze and articulate why I would use a hardware device over knots.

Here is a quick snapshot of the Piranha device I have:

  • Material: stainless steel
  • Weight: 27 g (0.95 oz) each
  • Length: 58 mm (2.3 in)
  • Width: 28 mm (1.1 in)

The device has a very cool form factor, and it reminded me of the Tarp Key from Smart Outdoors. I was hopeful that I could use the Piranha as an adjustment device for hanging a hammock, particularly with small diameter cord such as the spectra line Hennessy uses, or 7/64 Amsteel since the Piranha is built very strong.

However, as I’ve played with the Piranha, I’ve been hard-pressed to find a good fit for it. For example, it’s larger and heavier than most hardware used for tarps, so it’s really overkill there. And while the heavy-duty stainless steel is strong enough to hold human weight, when I tried hanging a hammock, the Piranha cut through the spectra line like butter.


Because of the way the line bends at sharp angles coming through the device, it puts a lot of strain on the cord. With enough tension, the edges (although beveled) are sharp enough to cause abrasion on the line.

The Piranha doesn’t improve on other key performance metrics that are important to me. It does not improve on speed, in fact it takes time to thread the cord through the eye, even though wrapping is fairly quick. It isn’t lighter than other hardware (a Whoopie Hook, in contrast, is a mere 3.4 g; nearly 24 g lighter!) , and the sharp turns and edges damage the cordage and pose risks to hammock and tarp fabric.

For me, the Piranha is more for show, and while I may use it on a keychain, I have no use for it as a knot replacement.