not herd of that one

[izzi]

Hi,

This was revealed on a previous topic, regarding torque settings.

"Undoing head bolts 1/4 turn, then retightening each in turn"

Many years ago before replacement bolts/studs came along, I was told that when you first torque dirt could be trapped which could give a false setting hence a second torque would be necessary as the dirt becomes flattened.
It may sound stupid yet the engineers I worked with thought it was there little secret.

Is there more myths out there or am I the the only one with a left handed screw driver.

Roy.

[bmcecosse]

Dirt?

[chrisryder]

Stiction. Sticking Friction.

Physics dictates that it requires more force to move a stationary object than to keep an object moving. If you tried to re-torque a tight bolt, then you will apply more torque to get it moving than it will be eventually torqued to.

If you back it off 1/4 turn then it reduces the torque slightly, so that when you do retorque you achieve the desired torque.

That's how I see it anyway.