How precise can modern machine tools make metal parts?

Modern machine tools are capable of achieving remarkable levels of precision when shaping metal parts. Standard modern equipment typically cuts or forms components to tolerances of plus or minus one ten-thousandth of an inch (0.0025 millimetre).1

For specialized applications requiring even greater accuracy, precision lapping machines can produce parts within a tolerance of plus or minus two millionths of an inch (0.00005 millimetre).1

Achieving these levels of precision requires a balance between heavy-duty structural rigidity and delicate mechanical accuracy to withstand the significant cutting forces involved in the manufacturing process. While designers must specify acceptable ranges—known as tolerances—to ensure parts function correctly, the ability to maintain such tight margins is essential for the production of high-quality, interchangeable parts.12