Review on 🔩 Bosch SpinLOCK Universal Hole Kit by Aravind Joshi

I have many sets of hole saws. They all have slightly different ways of attaching the saw blade to the mandrel. Usually in cheap kits it just bolts on or uses a screw. In any case, after repeated use, it is almost impossible to remove it without an impact wrench. So it's not very useful for quick changes. and removing the stub becomes a chore. That changes with the Bosch SpinLOCK mandrel. You simply align two pins, twist and lock. A powerful spring presses on the chuck, which holds it securely in the hole saw. The threads never tighten when cutting. The quill and pins do all the work. The retaining sleeve/ring is placed on the back of the cartridge and fixes it on the main mandrel. This system works very well. Changing the crown is very quick and easy without tools. It also makes it easier to remove the connector. No doubt it will increase my productivity on many tasks. Another feature I like is that the pilot bit can be easily changed to any quarter inch shank bit (see video). It locks into place with a ball detent. So you can quickly change it to a longer or shorter drill, a different diameter or a different drill type for different materials. Many possibilities. The downside is that without an Allen key, the bit wiggles a little to get it securely in place, which is the more common method. This can result in inaccurate hole centering. I can also imagine a situation where the drill bit gets stuck and if you pull on it it will loosen and stay in the wood. The crowns themselves are fine. The back wall is not very thick. Welded joint isn't the best I've seen. And the slits on the sides are quite narrow. They contain 8% cobalt in the alloy, which is said to improve heat resistance and durability. I tested them with different materials, mainly wood and plastic, and they all worked well. But not significantly better than many of my cheap import crowns, which is a bit disappointing given the price of this system. Overall I am very impressed with this tool. The mandrel is very innovative, easy to use and saves you tons of time when changing crowns and plugs. I also like the flexibility of the quick change pilot, although it comes with a few compromises. The price tag is definitely there. But I think it's obvious that this is a well-designed professional tool that should improve performance and last a very long time.