ASME B1.10M:1997 pdf download UNIFIED MINIATURE SCREWTHREADS
1 GENERAL
1.1 Scope
This Standard specifies the thread form, series, tolerance, and designation for the Unified Miniature ScrewThreads. The series covers a diameter range of 0.30mm to 1.40 mm,extending the metric M-Profile andunified thread series that begin at 1.6 mm.
1.2 Unified Miniature Screw ThreadStandards
The fourteen sizes published in this Standard wereendorsed by the American-British-Canadian conferenceof April 1955 as the basis of the unified standardamong inch-using countries,and to correspond withthe range of sizes in the ISO. The sizes are shown inTable 4. In interest of standardization and where designpermits, selection of size should be confined to thoseindicated in bold type in Table 4. For more restrictivcconditions, those sizes indicated in regular type in Table4 may be used.
1.3 Designation
Unified Miniature Thread sizes of this series shallbe designated on engineering drawings, in specificationsand on tools and gages (space permitting) by theirnominal diameter in hundredths of a millimeter followedby the symbol“UNM”(e.g., 0.80 UNM).On internal threads the full limits of minor diamneteras given in Table 6，shall normally be consideredapplicable. Where this is not permissible, the designationshall be supplemented by the minor diameter limits.
1.4 Reference Documents
The latest issucs of the following documents forma part of this Standard to the extent specified herein ANSI/ASME B1.7M2 Nomenclature，Definitions，andLetter Symbols for Screw ThreadsPublisher: The American Society of Mechanical Engi-neers, 345 East 47th Street, New York,NY 10017
ISO 68，ISO General Purpose Screw ThreadsISO/R1S01，ISO Miniature Screw ThreadsPublisher: International Organization for Standardization.3 rue de Varembe.1211 Geneva 20,Switzerland
1.5 Acceptability
1.5.1 Additional recommended methods for determining the acceptability of miniature screw threads willbe included as further experience with this threadstandard is reported. Until such time, agreements mustbe reached between purchaser and vendor rcgardingthe basis for determining acceptance since practicesare likely to differ considerably, particularly for externalthrcads. Where a free choice is possible, the proceduresgiven below,which are bcing used with considerablesuccess by some producers, are suggested.
1.5.2 External Threads. The major diameter ofthe external thread is measured by either contact gagingoptical 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 recommended. 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.
1.5.3 Internal Threads. The minor diameter ofthe internal thread is gaged with “GOand “NOT GO”plain cylindrical plug gages. All other elements arechecked only for assemble-ability limits by means ofa“GO thread plug gage, taking extreme care not todamage the thread. For the minimum material limitsof the internal threads, the accuracy and performance
