What's the Name of That Book??? discussion

A boy was kidnapped and made an apprentice blacksmith, after many years he tries to escape and has magical silver shackles but through his legs when he tries to escape. The Anvil of Ice by Michael Scott Rohan has been suggested, I am over half way through it and although the plot seems similar, it's not the same book.This is driving me mad, I got this book from the library in the 1980's and enjoyed it, there were more books in the series I think, but I never followed it up and now cannot remember the name of the book or the author, possibly the authors surname began with A but not too sure.

Was this a book for children, teens, or adults?

Where does the story takes place?

Anything about the villains, sidekicks, friends, family, etc?

Anything about the cover?

Were the shackles some sort of loop thing through/around the Achilles tendon? And there was some sort of emphasis on them being impossible to remove, or impossible for him to remove?
I remember something like that (mostly it stuck in my brain because it seemed impractical) but it was a long time ago I read it and I can't think of what the book was. If it seems like that might be the one you are looking for I'll try and figure it out.

Yes, you are right! i now know what the book is, it's the hammer of the sun by michael scott rohan. this is the third book in the winter of the world series, it had been suggested to me that it was the anvil of the ice, the first one, I read that and the shackles part was not in there so I posted on What's the name of the book, but have now solved the riddle, very good series by the way

thought I had put this in solved but seems I did it wrong

The Hammer of the Sun by Michael Scott Rohan for the link.