OCR Text |
Show Foundry Processes 4 Being Revolutionized One of the most revolutionary processes in a thousand years of j foundry practice is responsible for production by General Motors of the most accurate big castings ever ev-er known. With surface finish and a dimensional di-mensional accuracy hitherto undreamed un-dreamed of except in small "precision' "preci-sion' castings. GM is making enormous enor-mous retreading bolds for B-29 bomber tires, 00-pound aluminum tractor tire matrices and regulator regula-tor housings for aircraft propellers. propel-lers. Key to the achievement is one of the oldest principles of foundry |