Larger workpieces, looser tolerances?

摘要

LARGE WORKPIECES MAY BE machined to looser tolerances than small workpieces. Gerard Vacio of BIG Kaiser Precision Tooling Inc., cited aerospace parts as examples of often looser tolerances. "We have customers who have blueprints that say the hole can be within 0.008" or 0.009" of true position," Vacio said. "It will still work." The looser tolerances can result from the difficulty of maintaining feature-to-feature accuracy on large workpieces. A machine tool can have considerable trouble holding 0.0002" on location from one dowel pinhole to another if the two features are 8' apart.