1、Screw Thread Gaging Systems for Acceptability: Inch and Metric Screw Threads(UN, UNR, UNJ, M, and MJ)AN AMERICAN NATIONAL STANDARDASME B1.3-2007(Revision of ASME B1.3M-1992)Intentionally left blank ASME B1.3-2007(Revision of ASME B1.3M-1992)Screw ThreadGaging Systemsfor Acceptability:Inch and Metric
2、Screw Threads(UN, UNR, UNJ, M, and MJ)AN AMERICAN NATIONAL STANDARDThree Park Avenue New York, NY 10016Date of Issuance: October 12, 2007This Standard will be revised when the Society approves the issuance of a new edition. There willbe no addenda or written interpretations of the requirements of th
3、is Standard issued to this edition.Periodically certain actions of the ASME B1 Committee will be published as Cases. Cases are publishedon the ASME Web site under the Committee Pages at http:/cstools.asme.org as they are issued.ASME is the registered trademark of The American Society of Mechanical E
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9、art of this document may be reproduced in any form,in an electronic retrieval system or otherwise,without the prior written permission of the publisher.The American Society of Mechanical EngineersThree Park Avenue, New York, NY 10016-5990Copyright 2007 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSA
10、ll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster . vCorrespondence With the B1 Committee vi1 General. 12 Reference Documents 13 Screw Thread Gages and Measuring Equipment . 14 Gaging Systems 15 Gaging Requirements . 26 Acceptability 27 Designation. 3Tables1 Screw Thread Gages a
11、nd Measuring Equipment for External Product ThreadCharacteristics 42 Screw Thread Gages and Measuring Equipment for Internal Product ThreadCharacteristics 83 Gaging Systems for External Threads . 124 Gaging Systems for Internal Threads . 13iiiFOREWORD(a) The 1986 edition of this Standard was a combi
12、nation of ANSI B1.3-1979 and ANSIB1.3M-1981. These earlier versions of this Standard were based upon the following instructionsas defined by the B1 Committee at its meeting on October 7, 1976, which charged the B1.3Subcommittee with the responsibility of preparing these documents.The Subcommittee wa
13、s to prepare a catalog of gages and gaging systems so that each gage orgaging system would be defined only in terms of the dimension(s) controlled and so that anymaterial of an editorial nature that could be construed as giving preference to one gage or gagingsystem over another would be eliminated,
14、 as outlined in the following three statements:(1) All references to referee gaging methods are to be eliminated from all B1 documents.(2) A catalog of gaging systems is to be prepared by the B1.3 Subcommittee so that anydescription of the gage relates only to the specific dimension(s) it controls.
15、All material of aneditorial nature that could be construed as giving preference will be eliminated.(3) The level of dimensional acceptability shall be determined by the threaded productapplication and specified by American National Standards or other product standards, or byprocurement drawings or d
16、ocuments.Subsequently, the Subcommittee decided to combine these previous standards into one docu-ment and designate it ANSI/ASME B1.3M-1986, Screw Thread Gaging Systems for DimensionalAcceptability Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ).(b) The 1992 edition included the following s
17、pecific changes:(1) elimination of internal snap gages(2) addition of best wire size radius contacts to minimum material thread groove measure-ment gaging(3) clarification of out-of-round indicating gaging in Tables 1 and 2(4) addition of a reference to ASME B46.1, Surface Texture, to provide roughn
18、ess averageguidelines to be used for the evaluation of the surface texture of threaded products(5) addition of linear and coordinate measuring machines to the equipment included forthread evaluation(6) clarification that System 23 checks are not all mandatory(7) clarification relating to the measure
19、ment of changes in diameter size because of out-of-roundness conditions(c) The 2007 edition includes the following specific changes:(1) removal of the words dimensional and control(s), and replacement with the wording inspect/evaluate (and their related forms), because gages do not control the produ
20、ct dimension.(2) elimination of references to ASME B1.18M and B1.19M, due to those standards havingpreviously been withdrawn. This also eliminates any reference to System 21A and its gages aspreviously listed in Tables 1, 2, 3, and 4 (B and C NOT GO segments and rolls, commonly referredto as a doubl
21、e NOT GO).(3) elimination of the use of cast replica determination of pitch diameter (and related features)for internal product inspection/evaluation.(4) qualification notes under Tables 1 and 2 with regard to variable gage inspection offunctional diameter.(5) changed the numbering system in Tables
22、1, 2, 3, and 4 to provide consistency in numberingfrom table to table.Suggestions for improvement of this Standard are welcome. They should be sent to Secretary,ASME B1 Standards Committee, Three Park Avenue, New York, NY 10016-5990.This revision was approved as an American National Standard on Marc
23、h 5, 2007.ivASME B1 COMMITTEEScrew Threads(The following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSA. L. Barrows, ChairD. S. George, Vice ChairA. L. Guzman, SecretarySTANDARDS COMMITTEE PERSONNELG. L. Allen, L. S. Starret Co.A. L. Barrows, K
24、ennametal Industrial Products GroupF. G. Calderone, Corresponding Member, Quality SystemsImplementersL. N. Dixon, Jr., General ElectricR. Dodge, Pennoyer Dodge Co.G. A. Flannery, Corresponding Member, Mercury Gage Co.H. N. Frost, Defense Supply Center PhiladelphiaJ. O. Gehret, Vermont Thread GageD.
25、S. George, Ford Motor Co.J. R. Gervasi, Kerr Lakeside Inc.J. Greenslade, Greenslade Order Department: 22 Law Drive, Box2300, Fairfield, NJ 07007-23003 SCREW THREAD GAGES AND MEASURINGEQUIPMENT(a) Tables 1 and 2, for external and internal screwthreads, respectively, are listings of screw thread gages
26、,gaging elements, and measuring equipment.NOTE: Throughout the remainder of this Standard, the term gageincludes any gages, gaging elements, and measuring equipmentlisted 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 desig
27、nated fordetermining conformance.(b) The tables are arranged to establish product screwthread acceptance criteria based on recognized gagingconcepts used to assess conformance.(1) Attributes. Fixed limit inspection/evaluationprovides a qualitative assessment of a characteristic(s)using gages which d
28、etermine conformance.(2) Variables. Indicating control is a quantitativeand qualitative assessment on a characteristic(s) whichis 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-te
29、ms for inspection/evaluation of externally and inter-nally threaded products, respectively.(b) Three gaging systems for inspection/evaluationof threads on threaded products are established hereinto provide a choice depending on the engineeringrequirement of the threaded product. These are identi-fie
30、d as Systems 21, 22, and 23. The difference betweengaging systems is the level of inspection/evaluationdeemed necessary to satisfy that conformance has beenachieved.(c) Since most screw thread applications do notrequire that all of the characteristics described in theASME B1.3-2007applicable product
31、 specifications, standards, and appli-cations documents be inspected/evaluated, selection ofthe appropriate gaging system will be based on thosecharacteristics important to the end use. Considerationshould be given to such factors as form, fit, function,and fabrication of the threaded product. Measu
32、rement/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 threeestablished gaging systems is as follows:(1) System 21. Provides for interchan
33、geable assem-bly with functional size inspection/evaluation at themaximum material limit within the length of standardgaging elements, and also inspection/evaluation ofcharacteristics identified as NOT GO functional diame-ters or as HI (internal) and LO (external) functionaldiameters.(2) System 22.
34、Provides for interchangeable assem-bly with functional size inspection/evaluation at themaximum material limit within the length of standardgaging elements, and also inspection/evaluation of theminimum material size pitch diameter or thread groovediameter over the length of the full thread. The cumu
35、la-tive effects of all other thread characteristics such aslead, flank angle, taper, and roundness variations areconfined within product tolerance limits with no specificinspection/evaluation of their magnitudes.(3) System 23. Provides for interchangeable assem-bly with functional size inspection/ev
36、aluation at themaximum material limit within the length of standardgaging elements, and also inspection/evaluation of theminimum material size pitch diameter or thread groovediameter over the length of the full thread. The magni-tude of other thread characteristics such as lead, flankangle, taper, a
37、nd roundness are further inspected/evalu-ated, as specified within the pitch diameter limits. Onlythread characteristics in System 23 for which require-ments or limitations are specified must be inspected/evaluated for System 23 compliance. For example, if theproduct thread has no surface texture re
38、quirement normajor-to-pitch runout limitation, then System 23 doesnot require that these two characteristics be checked.(d) For special applications, the screw thread on athreaded product may require inspection/evaluationnot consistent with any of the standard gaging systems.In such cases, one of th
39、e standard gaging systems shouldbe selected and modified by specifying, in accordancewith para. 7(b), the addition or the reduction of threadcharacteristic(s) and gage(s) as selected from Table 1 or2, as applicable.(e) Product threads affected by roundness variationsmay be even-lobed (180 deg contac
40、t) or odd-lobed(120 deg contact). Product thread acceptance or rejectioncan be influenced by thread gages and measuring equip-ment having the ability to detect one, but not both,2because of gage design. Tables 1 and 2 provide a selectionof gages which in combination may be needed to assurethat diame
41、ter size variations caused by out-of-round-ness are contained within product tolerance limits.5 GAGING REQUIREMENTS(a) Screw threads of threaded products are defined bythe applicable thread document. Appropriate standardsare listed in section 2.(b) The gaging system used to inspect/evaluate thescrew
42、 thread of a threaded product shall be as specifiedin the product standard, procurement drawing, or pur-chase inquiry and order. In the absence of a specifiedgaging system on the purchase order, product drawing,or other applicable documentation, the supplier and cus-tomer must agree upon a suitable
43、gaging system. Thereis no implied default gaging system.(c) Each of the thread characteristics specified in thegaging system shall be inspected/evaluated using thegage (or one of the gages) specified for that characteris-tic. Gages shall be in conformance with the applicablegaging documents. Use app
44、ropriate standards listed insection 2 unless otherwise specified.(d) The use of any gage or measuring device is notprecluded if the results given by such gage or measuringdevice correlate with a gage or measuring device listedin this Standard.(e) All measurement results are not necessarily equalto a
45、 characteristics true size. The environment, theinstruments, and the operator are factors influencingmeasurement results. The sum of these factors may becumulative, making the measurement results furtherfrom the characteristics true size, or the factors maycancel each other out, making the measureme
46、nt resultscloser to the characteristics true size.6 ACCEPTABILITY(a) The screw thread of a threaded product shall beacceptable when each of the thread characteristics speci-fied in the designated gaging system is found to beacceptable.(b) Within each gaging system, a choice of gages isspecified for
47、each characteristic. Acceptance by any onegage in current calibration specified for a characteristicshall be the criterion for acceptance of that characteristic.(c) All threaded products are subject to visual inspec-tion/evaluation for gross defects. This visual inspec-tion/evaluation shall be made
48、without magnificationand is intended to detect such gross defects as missingor incomplete threads, defective thread profile, torn orruptured surfaces and cracks, etc. Surface texture ofthreaded products, when required, will be inspected/evaluated by visual or tactile comparison with texturespecimens
49、 or surface measurement equipment.ASME B46.1 provides roughness average (Ra) guidelinesASME B1.3-2007for various thread manufacturing processes.(d) Relationship of Gaging Systems to Product ScrewThread Acceptability(1) Product screw threads acceptable to System 23are acceptable where Systems 22 and 21 are specified.(2) Product screw threads acceptable to System 22are acceptable where System 21 is specified.7 DESIGNATION(a) Thread acceptability requirements as described inthis Standard must be specified in addition to threadsize designation and thread class specified in accordancewit
