Yep Loki is correct he did say it was a Frag.My bad
As far as time between between actions from my experance normally 6 seconds from when the pin is pulled to exploding. However as Ody is holding it after the pin has been pulled it would take 4 seconds till exploding. The chemical process has already begin and is only waiting for the arming device to be removed so it can arm itself fully.
We used the pop and hold method in training and Panama to quicken the explosion rate so as not to have an opposing soldier, as crazy as it sounds, actually pick it up and try to throw it back. What you see in the movies about that happening is very very rare even on a 6 second timer. We had Veteran sergeants tell us during training that it all depended on the distance between pull and landing as grens are close in weapons except those fired by launchers like the old M79 or the underbarrel M203.