We've been using these specifically for a couple years and then a variation before that. Very useful and sturdy, but do get loose after allot of use, I'd say many 6-8 months in- depending if they are before or after Spring. Great product.
I have two of these, and they are rugged, stay sharp, and easy to maintain. I love them.
I love the sharpness, the glide. My old ones required so much more strength to do the same task. I can only imagine what it would be like if I had bought a longer handle model, but this one fits my tasks.