1、Metric Practice Guide for the Welding IndustryAWS A1.1:2016An American National StandardAWS A1.1:2016An American National StandardApproved byAmerican National Standards InstituteAugust 30, 2016Metric Practice Guide for the Welding Industry Supersedes AWS A1.1:2001Prepared by theAmerican Welding Soci
2、ety (AWS) A1 Committee on Metric PracticeUnder the Direction of theAWS Technical Activities CommitteeApproved by theAWS Board of DirectorsAbstractThis metric practice guide is based on the International System of Units (SI) as defined in the U.S. Federal Register notice of July 28, 1998, “Metric Sys
3、tem of Measurement: Interpretation of the International System of Units for the United States.” It includes the base units, derived units, and rules for their use. Also covered are conversion factors and rules for their use in converting U.S. customary units to SI units.Recommendations are presented
4、 for style and usage in such areas as prefixes, punctuation, number grouping, etc. There are also suggestions to industry for managing the transition.AWS A1.1:2016iiISBN: 978-0-87171-896-92016 by American Welding SocietyAll rights reservedPrinted in the United States of AmericaPhotocopy Rights. No p
5、ortion of this standard may be reproduced, stored in a retrieval system, or transmitted in any form, including mechanical, photocopying, recording, or otherwise, without the prior written permission of the copyright owner. Authorization to photocopy items for internal, personal, or educational class
6、room use only or the internal, personal, or educational classroom use only of specific clients is granted by the American Welding Society provided that the appropri-ate fee is paid to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, tel: (978) 750-8400; Internet: .AWS A1.1:2016
7、iiiStatement on the Use of American Welding Society StandardsAll standards (codes, specifications, recommended practices, methods, classifications, and guides) of the American Welding Society (AWS) are voluntary consensus standards that have been developed in accordance with the rules of the America
8、n National Standards Institute (ANSI). When AWS American National Standards are either incorporated in, or made part of, documents that are included in federal or state laws and regulations, or the regulations of other governmen-tal bodies, their provisions carry the full legal authority of the stat
9、ute. In such cases, any changes in those AWS standards must be approved by the governmental body having statutory jurisdiction before they can become a part of those laws and regulations. In all cases, these standards carry the full legal authority of the contract or other document that invokes the
10、AWS standards. Where this contractual relationship exists, changes in or deviations from requirements of an AWS standard must be by agreement between the contracting parties.AWS American National Standards are developed through a consensus standards development process that brings together volunteer
11、s representing varied viewpoints and interests to achieve consensus. While AWS administers the proc-ess and establishes rules to promote fairness in the development of consensus, it does not independently test, evaluate, or verify the accuracy of any information or the soundness of any judgments con
12、tained in its standards.AWS disclaims liability for any injury to persons or to property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance on this standard. AWS also makes
13、no guarantee or warranty as to the accuracy or completeness of any information pub-lished herein.In issuing and making this standard available, AWS is neither undertaking to render professional or other services for or on behalf of any person or entity, nor is AWS undertaking to perform any duty owe
14、d by any person or entity to someone else. Anyone using these documents should rely on his or her own independent judgment or, as appropriate, seek the advice of a competent professional in determining the exercise of reasonable care in any given circumstances. It is assumed that the use of this sta
15、ndard and its provisions is entrusted to appropriately qualified and competent personnel.This standard may be superseded by new editions. This standard may also be corrected through publication of amend-ments or errata, or supplemented by publication of addenda. Information on the latest editions of
16、 AWS standards includ-ing amendments, errata, and addenda is posted on the AWS web page (www.aws.org). Users should ensure that they have the latest edition, amendments, errata, and addenda.Publication of this standard does not authorize infringement of any patent or trade name. Users of this standa
17、rd accept any and all liabilities for infringement of any patent or trade name items. AWS disclaims liability for the infringement of any patent or product trade name resulting from the use of this standard.AWS does not monitor, police, or enforce compliance with this standard, nor does it have the
18、power to do so.Official interpretations of any of the technical requirements of this standard may only be obtained by sending a request, in writing, to the appropriate technical committee. Such requests should be addressed to the American Welding Society, Attention: Managing Director, Technical Serv
19、ices Division, 8669 NW 36 St, # 130, Miami, FL 33166 (see Annex J). With regard to technical inquiries made concerning AWS standards, oral opinions on AWS standards may be rendered. These opinions are offered solely as a convenience to users of this standard, and they do not constitute professional
20、advice. Such opinions represent only the personal opinions of the particular individuals giving them. These individuals do not speak on behalf of AWS, nor do these oral opinions constitute official or unofficial opinions or interpretations of AWS. In addi-tion, oral opinions are informal and should
21、not be used as a substitute for an official interpretation.This standard is subject to revision at any time by the AWS A1 Committee on Metric Practice. It must be reviewed every five years, and if not revised, it must be either reaffirmed or withdrawn. Comments (recommendations, additions, or dele-t
22、ions) and any pertinent data that may be of use in improving this standard are requested and should be addressed to AWS Headquarters. Such comments will receive careful consideration by the AWS A1 Committee on Metric Practice and the author of the comments will be informed of the Committees response
23、 to the comments. Guests are invited to attend all meetings of the AWS A1 Committee on Metric Practice to express their comments verbally. Procedures for appeal of an adverse decision concerning all such comments are provided in the Rules of Operation of the Technical Activities Committee. A copy of
24、 these Rules can be obtained from the American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.AWS A1.1:2016ivThis page is intentionally blank.AWS A1.1:2016vPersonnelAWS Committee on Metric PracticeG. D. Uttrachi, Chair WA Technology, LLCJ. Letki, Vice Chair General ElectricS. P. Hedrick, Sec
25、retary American Welding SocietyB. B. Barrow Defense Information Systems Agency, retiredJ. R. Frysinger Metric Methods; College of Charleston, retiredE. A. Mechtly University of IllinoisAdvisors to the AWS Committee on Metric PracticeJ. Liu Subsea Technology IncA. Rabinkin Metglas Inc Hitachi MetalsS
26、. K. Saha New York State Department of TransportationAWS A1.1:2016viThis page is intentionally blank.AWS A1.1:2016viiForewordThis foreword is not part of this standard but is included for informational purposes only.The AWS Metrication Policy states, in part, “The AWS supports a timely transition to
27、 the use of SI units.” At the present time, the U.S. stands alone as the only industrial country that still predominantly uses the inch-pound units of measure-ment. Since the signing of the Metric Act of 1975 and an initial flurry of transition, the voluntary feature of the Act allowed the impetus t
28、o stagnate. The U.S. industrial and commercial productivity, mathematics and science education, and the competitiveness of our products and services in world markets would be enhanced by the adoption of the metric system. Americans have, so far, only made ineffective attempts at public education and
29、 awareness of the metric system.It is of historical interest that in the late 1700s Benjamin Franklin and Thomas Jefferson strongly supported decimal measurement and decimal currency. They were successful in having the US use a decimal currency but not the decimal measurement system they also promot
30、ed. In fact, in 1790 George Washington in his first annual message to Congress reminded the legislators “Uniformity in the currency, weights, and measures of the United States is an object of great importance, and will, I am persuaded, be duly attended to.” The metric system of measurement was part
31、of the reforms Napoleon enacted and it was spread to all the lands under his control. This coherent method of measurement served to fuel the scientific progress of the coming decades. The USA, in fact, had a major influence on the measurement leaders in France, who were developing the decimal metric
32、 system to become the legal French measuring system. It should be noted that, by acts of Congress, the metric system has been legal for use in all commercial and legal dealings in the US since 1866 and it was declared to be the “preferred system of measurement” in 1988.Simple conversation is not the
33、 answer. The use of two different unit systems was the cause of the loss of the Mars Climate Orbiter. NASA specified metric units for its design and construction but one subcontractor provided thruster performance data in pound force seconds instead of newton seconds. The spacecraft was intended to
34、orbit Mars at 150 kilometers altitude, but incorrect data caused it to descend instead to about 57 kilometers burning the orbiter up in the Martian atmos-phere. In addition to being a source of errors, simple mathematical conversion creates inconsistencies in allowable toler-ances. It also causes ex
35、tra cost when rounding causes tighter tolerances than specified in the original design. Even the countries that were using metric measurement had to make compromises and changes to have a truly uniform system, which we now refer to as SI (International Standard.) A recent example was the value of a
36、teaspoon, which was different in several countries. When dispensing medicine an accurate value is critical. There is now a unified SI value for this measure. The AWS Metric Practice Committee has tried to remain congruent with these unification changes, as have other Societies such as IEEE and ASME.
37、The American Welding Society has made significant progress in including SI units in our standards documents and in our published Welding Journal. This has helped make them accepted World Wide. This 6thedition reflects the current “state of the art” in SI practice for the U.S. welding industry and wi
38、ll assist the welding industry in converting to SI units and promote their voluntary use.Comments and suggestions for the improvement of this standard are welcome. They should be sent to the Secretary, AWS Committee on Metric Practice, American Welding Society, 8669 NW 36 St, # 130, Miami, FL 33166.
39、AWS A1.1:2016viiiThis page is intentionally blank.AWS A1.1:2016ixTable of ContentsPage No.Personnel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vForeword . . . . . . . . . . . .
40、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .viiList of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41、. . . . . . . . . . . . xi1. Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12. The International System of Units (SI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42、 . . . . . . . . . . . . . . . . . . . . . . . . . .12.1 Completeness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12.2 Coherence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22.3 Uniqueness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22.4 Advantages of the SI . . . . . . . . . . . . . . . . .
44、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23. SI Units and Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23.1 SI Base Units . . . . . . . . . . .
45、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23.2 SI Derived Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23.3 Prefixes . .
46、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24. Other Units Used with SI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47、. . . . .25. Units Pertaining to Welding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56. Style and Usage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
48、. . . . . . . . . . . . . . . . . .56.1 Application and Usage of Prefixes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56.2 Mass, Force, and Weight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49、. . . . . . . . . . . . . . . . . . . .66.3 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86.4 Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86.5 Angles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86.6 Stress and Pressure . . . . . . . . . . . . . . . . . . .
