Was using a torque wrench set at 12 N.m as stated in the manual. Snapped one of the bolts. Was lucky and was able to unscrew the remaining bolt out of the casing which was jutting out with a pair of pliers. This is about the 7th time to change the oil filter on the bike. Do these bolts stretch over time, and need replacing ? Should I replace all the bolts next time I change the oil element ? I don't want a repeat performance. I might not be so lucky next time and have to drill snapped bolts out of casings. Anyone have similar experience, advice ? Cheers all.