Does an oil drain plug become stripped when putting it in or taking it out?

I had my oil changed in August and the place said that my drain plugged had been stripped last time my oil was changed (at a different place). I told them it wasn't leaking and wouldn't it be leaking if damaged last time and they said no. They replaced it with another plug, not similiar to the original. A few days later my car started leaking oil. I took it to a mechanic and he had to replace the oil pan because he said the plug had ruined the pan and couldn't be re-tapped. I went back to the place that changed my oil and they said the original plug was not stripped by them and that the plug they put in didn't cause any damage to the oil pan. I'm out a lot of money. Does anyone know who is at fault, without seeing the plugs of course.Does an oil drain plug become stripped when putting it in or taking it out?
Most times stripping comes while putting in. They start it at an angle or way over tighten it, but it won't leak. The problem comes when you remove it, the bolt is stripped (Cross Threaded) pan is the same and no matter what when you reinstall it it's going the leak and maybe even fall out. The only thing that can really be done is they (Where you are at this time) is try to rethread the pan and install a new oil pan plug.Does an oil drain plug become stripped when putting it in or taking it out?
Its very hard to place blame. A plug can be stripped out if overtightened, but in most cases, plugs and the oil pan threads do wear and become loose over time. If your vehicle has a lot of mileage and the oil is changed often, it could be the threads just worn out.
Honestly, it's impossible to say.





It's even possible that this new place you took it to did all the damage and they are simply blaming the prior place for damage that was caused by them.





Most reputable places, if they see the bolt was damaged by the prior place will actually refuse to perform the service for you because they can see the damage that was done by the prior place.





If they were going to replace the plug, why didn't they use a similar plug? What were the differences? If they used an improperly threaded bolt, then of course they are at fault. How to prove it is a whole other story unfortunately.





It sounds like this place you took it to damaged the threading, to the oil pan and caused all the problems, but it will be very difficult for you to prove it.
Without seeing the plugs, you just have to suck it up and pay the money. Somebody stripped the plug and just hoped it would hold until you made it off of their lot. This is why mechanics have such a bad name.