A slightly related question spawned this one. Sweden made a lot of ball bearings during WW2, which it exported to Britain and Germany. How many tons of ball bearings were imported from Sweden to Britain per year? How many tons was Britain manufacturing itself, and how many tons was imported from America?
I found this pdf and looked through it, but does not provide a full answer. It only speaks in relative terms and financial terms. It even seems to contradicts itself, saying 31% of British ball bearings were from Sweden in the first page, but later down says "Direct wartime imports from Sweden provided about 15% of all British ball bearings."
What we really need to know is how many tons of ball bearings were made in America and Britain. America was already convoying much stuff to Britain, and I suspect that if Sweden was totally cut off, American production could step up.