Our permanent spines, removable spines and Quick Wick® spines are all made from pure Stainless Steel aircraft cable for a blend of shock-absorbing flexibility and rigidity. These resilient spines spring back into shape when the firehoop hits the ground or is stuffed into a car.
The type of stainless steel used is much like "spring steel" and allows for a certain amount of abuse. However, like any material, continuous back-and-forth flexing, impacts and extreme temperature changes can all effect the lifespan of a cable spine. Most materials exposed to extreme temperature changes will slowly become more brittle over time as it goes from cold to hot to cold again and again. This is an additional consideration when lighting up most fire props from a very cold state.
Although steel cable cannot get any stronger, nor has a better material proven more suitable, a spine is often the first thing to become damaged on a firehoop or a Quick Wick®. Think of a metal paper clip opened up and continuously bent back & forth... eventually after some unpredictable amount of bends, the paper clip will snap at the worn-out bend spot. It could take 20 bends or it could take 100, but the less abuse it takes, the longer it will last.
Steel cable is made from a similar type of steel as a paper clip is composed of multiple wire strands and is why it is also called "wire rope." This offers the cable flexibility & resilience ..but even still, a strand can break. If this happens, it means your cable has gotten stressed out and is nearing the end of its life. Although there are many other strands still holding strong, the cable is now slightly weakened and it will take less and less force to continue breaking strands. Once a strand or two break, the spine should be replaced. See our Warranty & Repairs page for details.
Most cable spines last for many years. What keeps them in their best shape is fewer drops. Additionally, remember that there is no need to shake your firehoop to wobble the wicks, even though it feels fun & bouncy. This is essentially bending the spine back and forth. That said, spines can easily outlast the wick or even the tubing, which is the easiest of the materials to damage because the fire can melt it.
In the end, it will be nothing short of plain and simple use that will wear a spine out over time. The act of lighting the wick on fire and blowing it very hot (from spinning it) repeatedly will cause drastic temperature changes, bringing the steel one tiny degree more brittle after every use.
We've seen spines last indefinitely, but differences in use, frequency, fuel, outside temperature and drops will all play a role in the lifespan of your spine. Take care of your firehoop, but if a spine does ever break contact us for repair. We are happy to keep these precious instruments in everlasting fiery flow.
Cable with 19 wire strands is more flexible than cable with 7 strands. When a firehoop drops on the ground or a spine receives impact & bends, 1x19 cable-spines spring back to their original shape (straight) better than 1x7 cable spines which are more rigid / less flexible. The 1x7 cable gives the firehoop a much more solid feel, with less bounce or wiggle in the spines. However, being less flexible, 1x7 will retain bends more easily which means when dropped, a spine may retain a bend until bent back straight by hand (make sure the cable spine is cool enough to touch!). We typically use 1x19 for our shorter spines and 1x7 cable for our longer spines.