ANSIASME B1 美国螺纹标准.pdf

Abstract of
C REW
GAGES AND GAGING FOR UNIFIED
ANSIASME
INCH SCREW THREADS
31.2
READS
1983(R2001)
IFI NOTES
1. ANSIIASME B12 is a standard developed through the procedures
of The American Society of Mechanical Engineers. B1.2 is under
the jurisdiction of ASME Standards Committee B1
2. B1.2 specifies the purpose, use, basic design, size limits, tolerances,
and identification of thread gages and measuring equipment com-
monly used to inspect the dimensional acceptability of Unified inch
screw threads, All of the thread gages and devices listed in ASME
B1.3M, page A-63, are included in B1. 2.
3. This abstract of B1. 2 is limited to basic gaging principles and prac.
tices, and the purpose and use of each type of thread gage and
thread measuring device. Omitted are gage illustrations, design
specifics and gage tolerances. For the omitted information, refer
to the complete B1. 2, copies of which are available from ASME.
4. ANSI/ASME B1.2-1983 (R 2001) is abstracted with the permission
of its publisher, The American Society of Mechanical Engineers,
Three Park Avenue, New York, NY 10016-5990, U.S.A.
Introduction
2
Basic Principles
This standard provides essential specifi
2.1 Accuracy in Gaging
cations and dimensions for the gages used on
Thread plug gages are controlled by di-
Unified inch screw threads(UN and UNR thread
rect measuring methods. Thread ring gages,
form), and covers the specifications and dimen
thread snap limit gages, and indicating thread
sions for the thread gages and measuring equip
gages are controlled by reference to the appro
ment listed in Tables 1 and 2.(F/ Note: Same
as Tables 1 and 2 of ASME B1. 3M, pages A-
priate setting gages or direct measuring meth
ods or both
64 thru A-67. The basic purpose and use of
each gage are also described.
2.2 Limitations of Gaging
1.1 Reference Documents
2.2.1 Product threads accepted by a gage of
one type may be verified by other types. It is
(Refer to the complete standard, see possible, however, that parts which are near a
page N-43)
limit may be accepted by one type and rejected
by another. Also, it is possible for two individual
1.2 Classification
limit gages of the same type to be at opposite
extremes of the gage tolerances permitted, and
In this standard, the term NOT GO, pre.
orderline product threads accepted by one gage
viously known as HI and LO, is used to identify
could be rejected by another. For these rea-
unctional diameter thread gages
sons, a product screw thread is considered ac
A-72
a 2003 Industrial Fasteners institute