WOW !! I'm blown away at some of the response to a simple heads up to what I thought might be of some interest to anyone doing their own basic preventative maintenance.
It's a well known fact that spark plugs that are left in an aluminum head for extended period's of time run the risk of damaging the threads upon removal.
Perhaps that's why there is also a special tool, purpose built to repair damaged sparkplug threads.
Most mechanic's will warn you of the possibility before they remove sparkplugs on high mileage engine's regardless of brand if the heads are Aluminum.
I was contemplating giving Snap-On a call first thing in the Am to ask them what the heck they were thinking coming up with such a silly worthless tool but then I meet up with my local Snap-On dealer to show him this thread. He was equally amused, then he pulled up his records and showed me proof that he had sold 36 of these in the first week they were available. So I decided against calling .After all, they are the world leader in tools, the company with a brand loyalty like no other, why would they listen to me.
I change mine every spring along with the engine oil, transaxel oil, Oil pump belt, and air cleaner elements. Is that too often? Well that's a matter of opinion. Do my plugs go bad after just one season of driving ? Heck no they don't but I change them regardless and im very careful doing so. Silly me for thinking I might bring this to everyone's attention.
There is a highly respected member of this Forum that lost the top of a piston as a direct result of a poorly installed sparkplug. I know for a fact that his plugs are now being replaced annually.
O well I should have known better, Don't worry though. It wont happen again.