Bolt re-use

[CaseyJay]

Hi, I'm sure this topic is done to death but....

• Elsawin says always replace hub bolt
• My Audi tech says my bolt can be reused (when I went to buy a replacement from him)

sure my old one is not original (std hex head #27mm socket, not allen key type) as Audi tech showed me one with a washer built in.

so, are they safe to reuse? Risk snapping when pushed beyond torque? thx

[JimTraining]

Hello, sure one of our learned colleagues would advise more specifically, bolt initial torque (M14 115Nm, M16 190Nm) is the standard torque for the bolt, the torque turn of 180 degrees above this adds the "stretch" to the bolt. As the bolt is "stretched" it is generally best practice to replace the bolt as although the tension in the bolt is still below the tensile limit, multiple re-use can be an issue, hence a new one coming with most CV kits. Lots of other bolts are similar on various bits of kit e.g. cylinder head bolts, big end and main journal bolts. For the cost, I would change them.

I would be interested to know if lubricating the bolt is recommended or not. Torque turn is often used to avoid false tightening torques (as well as "stretch") which can result if bolts / threads are lubricated or not.

Cheers

[Crasher]

If the book of words says thou must change a fastener one must adhere to this diktat. We do and it causes us endless delays even though we have hundreds of different genuine fasteners in stock.