These needle roller bearings are designed for use in a closed environment where the outer housing fits into a machined bore and the shaft is perfect inside diameter (machined and within tolerance). They don't work well on their own, nor do they work outdoors where dirt and dust can be present without protective seals. They're very tough, but they have their limits. I've tried using them in slow speed applications where the reels weren't protected and while they did a pretty good job for a while, they failed on a task where ball bearings continue to work well.