ASME B1.10M:2004 pdf download UNIFIED MINIATURE SIREW THREADS
1.1 Scope
This Standard specifies the thread form, series, toler.ance, and designation for the Unified Miniature ScrewThreads The series covers a diameter range of 0.30 mmto 140 mm, extending the metric M-Profile and unifiedthread series that begin at 1.6 mm.
1.2 Unified Miniature Screw Thread Standards
The fourteen sizes published in this Standard wereendorsed by the American-British-Canadian conferenceof April 1955 as the basis of the unified standard amonginch-using countries, and to correspond with the rangeof sizes in the ISO. The sizes are shown in Table 1. Ininterest of standardization and where design permitsselection of size should be confined to those indicatedin bold type in Table 1. For more restrictive conditions,those sizes indicated in regular type in Table 1 maybe used.
1.3 Designation
Unified Miniature Thread sizes of this series shall bedesignated on engineering drawings, in specificationsand on tools and gages (space permitting) by their nominal diameter in hundredths of a millimeter followed bythe symbol“UNM”(e.g.,0.80 UNM)On internal threads, the full limits of minor diameteras given in Table 2, shall normally be considered applica-ble Where this is not permissible, the designation shallbe supplemented by the minor diameter limits.
1.4 Reference Documents
The following is a list of publications referenced inthis Standard.
ASME B1.7,Nomenclature, Definitions, and Letter Symbols for Screw ThreadsASME B1.30M,Screw ThreadsStandard Practice forCalculating and Rounding DimensionsPublisher: The American Society of Mechanical Engineers(ASME International),Three Park Avenue, NewYork,NY 10016-5990; Order Department: 22 LawDrive, Box 2300,Fairfield,N 07007-2300
ISO/R15012,ISO Minature Screw ThreadsPublisher: International Organization for Standardization, 3 rue de Varembe, 1211 Geneve 20, SwitzerlandSuisse
1.5 Acceptability
Additional recommended methods for determiningthe acceptability of miniature screw threads will beincluded as further experience with this thread standardis reported. Until such time, agreements must be reachedbetween purchaser and vendor regarding the basis fordetermining acceptance, since practices are likely to dif-fer considerably, particularly for external threads. Wherea free choice is possible, the procedures given below,which are being used with considerable success by someproducers, are suggested.
1.5.1 External Threads. The major diameter of theexternal thread is measured by either contact gaging.optical projection, or laser inspection equipment. Allother dimensions, such as pitch diameter, lead, threadform, and minor diameter may be inspected by opticalprojection methods, with a magnification of 100X recom-mended. A suggested chart for this method is shownin Appendix A. The thread plug gages and the tap areinspected in a similar manner to externally threadedparts. Contact gaging, such as the use of “GO” and”NOT GOring gages, measuring wires, and set pluggages may be used for sizes 0.70 UNM and above.