Thankfully the bolt head was stripped only at the top. At the base it was still intact and the spanner which is closed from all sides (not ring spanner) did it.
Thank you for all the suggestions.. i'm sure we have enough material in this thread to open bolt in any condition now :) I did replace the drain bolt, but again this is an aluminium one.. dunno how long it will last.. regards, Kapil [Non-text portions of this message have been removed]
