Receiver Gages — Go Gages
and Functional Gages
James D. Meadows
Institute for Engineering & Design, Inc.
James D. Meadows, president of the Institute for Engineering and Design, Inc., has instructed more than
20,000 professionals in Geometric Dimensioning and Tolerancing and related topics over the last 30
years. He is the author of two current hardcover textbooks, a workbook and a 14-hour, 12-tape appli-
cations-based video training program on GD&T per the ASME Y14.5M-1994 standard on dimension-
ing and tolerancing. He is an ASME Y14.5.2 Certified Senior Level Geometric Dimensioning and
Tolerancing Professional. Mr. Meadows is a member of eight ANSI/ASME and ISO standards commit-
tees and serves as the chairman of the committee on Functional Gaging and Fixturing of Geometric
Tolerances. He is a journeyman tool and die maker and a graduate of Wayne State University.
Receiver gaging is one of the most effective ways to determine the functionality of workpiece features.
There are two members of the receiver or attribute gage family: Functional Gages and GO gages.
Functional and GO gages both determine feature compliance with a fixed size boundary; hence they are
considered attribute gages.
Functional Gages inspect compliance with a constant functional boundary commonly associated
with a worst mating condition. This boundary is known as a maximum material condition (MMC) concept
virtual condition boundary. Functional Gages are made to the MMC concept virtual condition boundary
of the features they inspect, then toleranced so they represent a situation worse than the features will face
in assembly conditions.
GO gages are used to determine compliance with the maximum material condition boundary of perfect
form required by several American National Standards (ANSI B4.4, ASME Y14.5, and ASME Y14.5.1).
19-2 Chapter Nineteen
This type of measurement is a physical representation of the theoretical principles of geometric
tolerancing of workpieces. It shows th