I replaced my serpentine belt tensioner on my 2000 Saab 9-5 today. I found the bolt to be very long and very difficult to remove using my fingers. A glove helped but the tensioner assembly is ready to fall and it binds on the screw. When I was ready to put it back in, I was looking for an alternative. I tried to cut off a hex key so I could use it with a ratcheting wrench but didn't get very far. Then I discovered that a 1/4" drive ratchet fit the 8mm hex bolt very well. Not something you want to apply much torque with, but makes screwing the bolt out (once you break it loose) and screwing it back in until it is snug (then tighten with a hex key) go much more quickly.