All you could claim through eBay is the cost of the item, including delivery.
Consequential damage isn't covered by eBay, this would be between you and the seller. I imagine you're looking at several hundred pounds for repairs, so it will be worth consulting a solicitor.
A lot may depend upon who you bought it from. If from a seller in China you can forget it (assuming that it was correctly fitted, using an unsuitable grade of steel sounds very much like a cheap Chinese copy). Ditto if it was bought from a private seller. If it was a UK business seller you may be in with a chance, but there's always a lot of uncertainty. Going to law is always a risk and there's no guarantee of getting your money back, even if the case is found in your favour. Good luck.