ASME B1.3-2007 pdf download.Screw Thread Gaging Systems for Acceptability: Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ).
1 GENERAL ASME/ANSI B47.1 , Gage Blanks 1 (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 Publisher: The American Society of Mechanical Engineers (ASME), Three Park Ave, New York, NY 1 001 6-5990; Order Department: 22 Law Drive, Box 2300, Fairfield, NJ 07007-2300 used. 3 SCREW THREAD GAGES AND MEASURING (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 .1 3M, Metric Screw Threads: M Profile 1 ASME B1 .1 5, Unified Inch Screw Threads (UNJ Thread Form) ANSI/ASME B1 .1 6M, Gages and Gaging for Metric M Screw Threads 1 ASME B1 .21 M, 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
5 GAGING REQUIREMENTS (a) Screw threads of threaded products are defined by the applicable thread document. Appropriate standards are listed in section 2. (b) The gaging system used to inspect/evaluate the screw thread of a threaded product shall be as specified in the product standard, procurement drawing, or pur- chase inquiry and order. In the absence of a specified gaging system on the purchase order, product drawing, or other applicable documentation, the supplier and cus- tomer must agree upon a suitable gaging system. There is no implied default gaging system. (c) Each of the thread characteristics specified in the gaging system shall be inspected/evaluated using the gage (or one of the gages) specified for that characteris- tic. Gages shall be in conformance with the applicable gaging documents. Use appropriate standards listed in section 2 unless otherwise specified. (d) The use of any gage or measuring device is not precluded if the results given by such gage or measuring device correlate with a gage or measuring device listed in this Standard. (e) All measurement results are not necessarily equal to a characteristic’s true size. The environment, the instruments, and the operator are factors influencing measurement results. The sum of these factors may be cumulative, making the measurement results further from the characteristic’s true size, or the factors may cancel each other out, making the measurement results closer to the characteristic’s true size.
for various thread manufacturing processes. (d) Relationship of Gaging Systems to Product Screw Thread Acceptability (1) Product screw threads acceptable to System 23 are acceptable where Systems 22 and 21 are specified. (2) Product screw threads acceptable to System 22 are acceptable where System 21 is specified. 7 DESIGNATION (a) Thread acceptability requirements as described in this Standard must be specified in addition to thread size designation and thread class specified in accordance with the applicable screw thread document. (1)Thread acceptability requirements may be spec- ified by a general note on the drawing or procurement document, stating a particular system and referencing ASME B1.3. EXAMPLES: (1) Acceptability of screw threads shown on this drawing shall be determined based on System 21, ASME B1.3. (2) Acceptability of screw threads shown on this drawing shall be determined based on System 22, ASME B1.3. (3) Acceptability of screw threads shown on this drawing shall be determined based on System 23, ASME B1.3.