My med action rod is rated for lures up to 5/8 oz. I have some 3/4 oz traps I would like to use. Could I damage my rod ?

You will be fine, 1/8oz over shouldn't hurt it... Just don't go try to throw 3oz hudds lol

Well I have a med heavy rod as well. But it doesnt have the give in it I like for a crankbait rod, but the med rod is under rated weight wise. So thought I would ask those in the know.

At 77 I have tried to BREAK a rod casting as hard as possible.  Never happened ............No ultralights used.

 

If you can toss the lure far enough & accurately enough ?  Perfect rod.

It should be ok to use it for that. 

I do it also and haven't had a problem.

As was said 1/8 more will be ok.

BUT, I don't know where the limit would be, I assume there would be one.

Someone a lot smarter than me will be along shortly.

Mike

Lure weight ratings are as subjective as the other "Specs" put on rods. Pay attention to how the rod feels and handles the weight and let common sense prevail. Unless you do a snap cast with a grossly over loaded rod you are not likely to experience a failure. 

DVT's above response is as good an answer as you'll get on this IMO. I would not worry much about an eighth of an ounce.

Someone a lot smarter than me will be along shortly.

Mike