> Why is machining stronger than casting? One reason is that billets are far less likely to have pores and other defects (caused by air bubbles) than a casting

> Why is machining stronger than casting? One reason is that billets are far less likely to have pores and other defects (caused by air bubbles) than a casting. > Is one method more energy efficient than the other? Which is more energy efficient depends on the application and expected life of the part. Casting several cheaper parts and paying to replace them may or may not be cheaper/more efficent if you look at the entire process (including shipping and human interactions with the part).