ASME B1.3-2007 pdf download

ASME B1.3-2007 pdf download.Screw Thread Gaging Systems for Acceptability: Inch and Metric Screw Threads.
1 GENERAL (a) This Standard presents screw thread gaging sys- tems suitable for determining the acceptability of UN, UNR, UNJ, M, and MJ screw threads on externally and internally threaded products. It establishes the criteria for screw thread acceptance when a gaging system is used. (b) A screw thread gaging system comprises a list of screw thread characteristics that must be inspected/ evaluated to establish the acceptability of the screw threads on a threaded product and the gage(s) which shall be used when inspecting/evaluating those charac- teristics. (c) Federal Government Use. This Standard is approved by the Department of Defense and federal agencies, and is incorporated into FED-STD-H28/20, Screw Thread Standards for Federal Services, Section 20. The use of this Standard by the federal government is subject to all the requirements and limitations of FED-STD-H28/20. 2 REFERENCE DOCUMENTS The latest issues of the following documents form a part of this Standard to the extent specified herein. ASME B1.1, Unified Inch Screw Threads (UN and UNR Thread Form) 1 ANSI/ASME B1.2, Gages and Gaging for Unified Inch Screw Threads 1 ASME B1.7, Screw Threads: Nomenclature, Definitions, and Letter Symbols 1 ASME B1.13M, Metric Screw Threads: M Profile 1 ASME B1.15, Unified Inch Screw Threads (UNJ Thread Form) ANSI/ASME B1.16M, Gages and Gaging for Metric M Screw Threads 1 ASME B1.21M, Metric Screw Threads: MJ Profile 1 ANSI/ASME B1.22M, Gages and Gaging for MJ Series Metric Screw Threads 1 ASME B46.1, Surface Texture (Surface Roughness, Waviness, and Lay) 1 1 May also be obtained from American National Standards Insti- tute, 25 West 43rd Street, New York, NY 10036. 1 ASME/ANSI B47.1, Gage Blanks 1 Publisher: The American Society of Mechanical Engineers (ASME), Three Park Ave, New York, NY 10016-5990; Order Department: 22 Law Drive, Box 2300, Fairfield, NJ 07007-2300 3 SCREW THREAD GAGES AND MEASURING EQUIPMENT (a) Tables 1 and 2, for external and internal screw threads, respectively, are listings of screw thread gages, gaging elements, and measuring equipment. NOTE: Throughoutthe remainder ofthis Standard, the termgage includes any gages, gaging elements, and measuring equipment listed in Tables 1 and 2. See para. 5(d). For each gage, these tables specify the thread charac- teristic(s) for which the gages are designated for determining conformance. (b) The tables are arranged to establish product screw thread acceptance criteria based on recognized gaging concepts used to assess conformance. (1) Attributes. Fixed limit inspection/evaluation provides a qualitative assessment of a characteristic(s) using gages which determine conformance. (2) Variables. Indicating control is a quantitative and qualitative assessment on a characteristic(s) which is then compared with limiting values in order to deter- mine if the characteristic(s) is in conformance. 4 GAGING SYSTEMS (a) Tables 3 and 4 present screw thread gaging sys- tems for inspection/evaluation of externally and inter- nally threaded products, respectively. (b) Three gaging systems for inspection/evaluation of threads on threaded products are established herein to provide a choice depending on the engineering requirement of the threaded product. These are identi- fied as Systems 21, 22, and 23. The difference between gaging systems is the level of inspection/evaluation deemed necessary to satisfy that conformance has been achieved. (c) Since most screw thread applications do not require that all of the characteristics described in the applicable product specifications, standards, and appli- cations documents be inspected/evaluated, selection of the appropriate gaging system will be based on those characteristics important to the end use. Consideration should be given to such factors as form, fit, function, and fabrication of the threaded product. Measurement/ gage design capabilities inherent in each inspection/ evaluation system should also be considered when com- paring the benefits of each system. Guidance for selec- tion of an inspection/evaluation system from the three established gaging systems is as follows: (1) System 21. Provides for interchangeable assem- bly with functional size inspection/evaluation at the maximum material limit within the length of standard gaging elements, and also inspection/evaluation of characteristics identified as NOT GO functional diame- ters or as HI (internal) and LO (external) functional diameters.