Originally Posted by
oldnslow2
Had one of the bottle cage bolts snap. it took some time to remove the remaining piece in the down tube bung. It was torqued to spec, but the bolt was alloy and the spec was for a steel bolt. I remove the other bolt and could see that it was stretched. After contacting the manufacturer I found they recommend a much lower torque spec, unfortunately they didn't specify it anywhere on the packaging of the cage. The cage was Bontrager... aka Trek.
Just glad the bung was not damaged. I've seen a seatpost bung that was cracked from over torque. Not a cheap fix.
Agree that bolts shouldn't be overtightened but the actual force that's applied to stretching a bolt is highly variable even if you are applying torque within 1%. How much lubrication is on the bolt threads and any mating surfaces of the bolt affect how much of the torque you apply is translated to stretching the bolt vs overcoming friction.
I guess my long winded point is that the Harbour freight torque wrenches are fine and won't wreck your bike.