Hi

I was trying to loosen the Rd today, But it was so tight so tight that i managed to crack to dropout, There was a small scratch on the dropout hanger,
There was no serious damage apart from that scratch on the hanger itself(the rear stay)
I put the wheel back on and spin quite few round and it turn straight and true,
But I still wasn't sure if it will affected the frame,

Any opinion?

Is it scratched or cracked? Big difference. If it is cracked, I would replace it. If it failed while riding, the derailleur could fall into the wheel, possibly resulting in more damage and/or a crash. Anyway, alloy hangers are designed to be 'consumables' and replacements are readily available.

Not sure what you're asking. Is it the hanger that is damaged or the frame at the 'base' of the dropout where the hanger bolts on?

Photo would help....

Sorry if i made it confusing,
I broke the dropout but it left some kind of scrath on the place where it bolt onto,
What i concern is When i was trying undo the rd from hanger i was using quite an excessive force that instead of turning the bolt it broke the hanger instead,
Just wonder if it left some damage that i could not see, Overall everthing look fine,
Will take some pics tomorrow,