I share the same experience as the other one star review. After using this product on the third spring I've ever used it on, the threads in one of the compressors snapped, causing the spring to decompress violently. Fortunately there were no injuries. I really wish I could give this thing five stars, but I can't for a tool that lasts a fraction of what should last a lifetime and could have cost me a couple of fingers. I would also like to add that the thread was well lubricated.