Ive just bought a set of easton carbon bars and for some reason my stem clamp worked slightly loose and the bars twisted in the clamp about an 1/8 of a turn .Befgore i tightend them up again i inspected the bars and theres a slight scratch line about 15mm long that was caused by the clamp .If this hasnt gone the complete circumference of the bar am i still ok to use them as they cost nearly £80.

It’ll almost certainly be fine- the top coating is really just like clearcoat on paint, and you’re not likely to have gone through it.

1 Install using a torque wrench/key
2 Use carbon paste
3 Don’t worry about the scratch, unless it has gone all the way through the laquer

The top layer is lacquer, not carbon. I have carbon bars with scratches in and ride them still, but at the end of the day, it’s all about if you feel comfortable riding them.

Yeh it was just like a white powder from the scratch which would imply a lacquer powder residue i guess ,thanks guys

paste and correct torque is key or they’ll be slipping again, don’t be tempted to over tighten.