What is the typical tolerance range for turning and milling?

• A. +-0.002-0.010 in
• B. +-0.005-0.015 in
• C. +-0.001-0.005 in
• D. +-0.010-0.020 in

Answer: (A)

Tolerance is how much a produced dimension is allowed to deviate from the intended size. In turning and milling, these tolerances are typically a few thousandths of an inch. For most parts, you’ll operate in a practical range around a few thousandths, with tighter tolerances possible when needed and looser tolerances acceptable for noncritical features. The range of about ±0.002 to ±0.010 inches captures that common spread: you can hold around 0.002 in when precision is important, but often parts are acceptable up to about 0.010 in depending on function and measurement methods. The other options either imply tolerances that are unusually tight for general turning/milling or too loose for typical production, so the stated range best reflects standard practice.