My friend Julian had a south-side factory that made bits and pieces for old cars. He had an OLD South Bend lathe he had acquired many years before, and South Bend wanted to buy it back. Its steel was tough, and South Bend had lost the art of making such high quality tools. They wanted to study it to discover the lost secret that they once knew.
Julian (rest his soul, dear friend) said that the secret was that the beds and ways of the lathes were seasoned. They had been left outside over a cold Chicago winter or two, and the freezing, thawing, expanding, and contracting of the steel resulted in it being tougher, stronger, and just plain better.
He wouldn’t sell.
South Bend went out of business, and the business of making the machine tools that would continue to build the world moved to Germany, Japan, and China.