What caused this rotor groove

[lsupcar]

What could cause this groove to be machined into my driver's side front fotor hat? Also shown is the rotor from the passenger side front. The guage pic is to give an idea of the depth.
Thanks.
Bill Z

[SVXRide]

have you looked at the brake caliper to see if there are any shiny/worn down areas?
-Bill

[Hocrest]

My guess would be one of the spring clips. Are they intact? Missing? Broken?

[SVXRide]

Originally Posted by Hocrest

My guess would be one of the spring clips. Are they intact? Missing? Broken?

Dave,
That's what I was thinking, too. Had to have been making an awful noise to have cut that groove....
-Bill

[SoCal LS-L]

I cant imagine anything besides a brake lathe cutting a groove that major in the rotor..... I would assume anything that got caught on the caliper would wear down and fall out well before removing that much steel from the rotor.

Still looks shiny though, must have been pretty recent.

[NeedForSpeed]

Originally Posted by SoCal LS-L

I cant imagine anything besides a brake lathe cutting a groove that major in the rotor..... I would assume anything that got caught on the caliper would wear down and fall out well before removing that much steel from the rotor.

Still looks shiny though, must have been pretty recent.

My guess is the guy that cut the rotors forgot to set the lathe stop, got distracted, and then,,

[lsupcar]

Thanks for the replys. I did not think the clips would be hard enough to score the metal. I included the picture of the caliper to demonstrate that there was nothing hanging down or out of the caliper making contact with the rotor.
The explanation is likely related to the car recently being in the shop to get both the front axles replaced and subsequently both the abs sensors when the abs system was acting strange after the axles were done. My guess would be that a tool or bolt of some sort got wedged between the caliper and hat for some time. What threw me off was that it appeared the other side also had some sort of ring around the hat at the same spot.
I will have to ask the shop tomorrow and see what they say.
Bill

[Hocrest]

I never would have thought that the clips could do that until I saw it happen.

[trophy956]

hi did you chceck you hardware ,ive seen brake hardware cut rotors off the hats on non vented disk

[NeedForSpeed]

Originally Posted by Hocrest

I never would have thought that the clips could do that until I saw it happen.

On one of your cars?