DOCUMENT RESUME 069 883 VT 017 558 TITLE Engineering Standards. U.S. Metric Study Interim Report. INSTITUTION National Bureau of Standards (DOC), Washington, D.C. REPORT NO NBS-SP-345-11 PUB DATE Jul 71 NOTE 258p. AVAILABLE FROM Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 (SIN 0303-0835, $2.00) EDRS PRICE MF-$0.65 HC- $9..87 DESCRIPTORS *Engineering Technology; *Government Publications; Government Role; International Programs; *Measurement Techniques; *Metric System; *National Surveys; Organizational Change; Systems Development IDENTIFIERS Metric Study Act of 1968; National Bureau of Standards; Public Law 90 472; U S Metric Study ABSTRACT This report is the 11th in a series of interim reports stemming from the U.S. Metric Study, which is being conducted by the National Bureau of Standards in accordance with the Metric Study Act of 1968 (Public Law 90-472). Although it mainly concerns the relationships of measurement units to engineering standards, the issue of international standards is also discussed. Findings indicate that engineering standards can be harmonized internationally without the U.S. changing its measurement units. The International System of Units (SI) will become the measurement units in international standards, which means many U.S. engineering practices will have to change. However, the impact and the extent of change can be minimized, depending on the degree of participation in the international forum and the specific engineering practice. Extensive resource materials are appended. (AG) A :Ai S1A1B fit PO; M( II! 0;' CUMMERCE PUULIGAT ION PA P.Tik,,1 ENT OF COMMERCE Nation 13urimu Stanr1F,/:,15 I1 U.S. METRIC SUBSTUDY REPORTS The of stillstudies of the I. Metric Studv. !..;,1111;:ted For 11:e pieparation oft comprehensic repoil to the ( ,,e published in the interim as :I series of NUS I he Hit, of the individual reports are listed below REPORTS ON SUBSTUDIES NUS SP345-1: bityrna I ional Standar& 1) 0..i.ndtcr 197o. Catalog. No. C13.1(1:3.)5-1. Price SI.2.5 NUS SP345-2: Federal Clovernment:I\ ilian Agencies tin press) NUS SP345-3.: Commercial Weights and Measures in press) NUS SP345-4: The Nlanufacturini2, Industry (in press) NUS SP345-5: Nonmanu:,cturing Businesses tin press) NITS SP345-6: Education (in press) NUS SI'345-7: The Consumer (in press) NUS SI'345-8: International Trade (in press) NITS SI'345-9: Department of Defense (in press) N ITS S!' 345- I 0: A I listory of the .Ntetric System Controversy in the United States (in press) NUS SP345-1 I:Engineering Standards. this publication NBS SP345- 1 2:Testimony of Nationally Representative Group, (in press) COMPREHENSIVE REPORT ON THE U.S. METRICSTUDY NUS S1'345: To he published in August 197 1 .1 hose publications with catalog numbers have ahead) beet;issued. anti may he purchased from the Superintendent of Documents. ( iovailment Printing Office, Washington. D.C. 20402 for the pricesindicated. Add one- fourth of the purchase price if the publication orderedis to he sent to a foreign address. Be sure to include the SD Catalog number%% ith our order. U.S. DEPARTMENT OF HEALTH. EDUCATION & WELFARE OFFICE OF EDUCATION THIS DOCUMENT HAS BEEN REPRO- DUCED EXACTLY AS RECEIVEDFROM THE PERSON OR ORGANIZATION ORIG- U.S. METRIC STUDY INATING IT POINTS OF VIEW OROPIN- IONS STATED DO NOT NECESSARILY REPRESENT OFFICIAL OFFICE OF EDU- CATION POSITION OR POLICY. INTERIM REPORT ENGINEERING STANDARDS Eleventh in a series of reports prepared for the Congress U.S. METRIC STUDY Daniel V. De Simone, Director National Bureau of Standards Special Publication 345-11 UNITED STATES DEPARTMENT OF COMMERCE MAURICEH.STANS, Secretary NATIONAL BUREAU OF STANDARDS LEWIS M. BRANSCOMB, Director Nat. Bur. Stand. (U.S.), Spec. Publ. 345-11, 264 pages (July 1971) CODEN: XNBSA Issued July 1971 For sale by the Superintendent of Documents. U.S. Government Printing Mice Washington. D.C.. 20402Price S2 Stock Number 0303-0835 (Order by SD Catalog No. C 13.10:345 -111. Price 52.00 LETTER OF TRANSMITTAL THE HONORABLE PRESIDENT OF THE SENATE THE HONORABLE SPEAKER OF THE HOUSE OF REPRESENTATIVES SIRS: I have the honor to present the eleventh in the series of interim reports stemming from the U.S. Metric Study, prepared by the National Bureau of Standards. This Study was authorized by Public Law 90-472 toredu.;e the many un- certainties concerning the metric issue and to provide a better basis upon which the Congress may evaluate and resolve it. I shall make a final report to the Congress on this Study in August 1971. In the meantime, the data and opinions contained in this interim report are being evaluated by the Study team at the National Bureau of Standards. My final report to you will reflect this evaluation. Respectfully submitted, Secretary of Commerce Enclosure iii LETTER OF TRANSMITTAL Honorable Maurice H. Sums Secretary of Commerce Dear Mr. Secretary: have the honor to transmit to you another interim report of the U.S. Met- ric .Study. whiCh is being conducted at the National Bureau of Standardsat your request and in accordance with the Metric Study Act of 1968. The Study is exploring the subjects assigned to it with great care. We have tried to reach every relevant sector of the society to elicit their viewson the metric issue and their estimates of the costs and benefits called for in the Metric Study Act. Moreover. all of these sectors were given an opportunity to testify in the extensive series of Metric Study Confeiences that were held last year. On the basis of all that we have been able to learn from these conferences. as well as the numerous stirveys and investigations, a final repOrt will be made to you before August 1971 for your evaluation and decisionas to any recommendations that you may wish to make to the Congress. The attached interim report includes data and other opinions thatare still being evaluated by us to determine their relationship and significanceto all of the other information that has been elicited by the Study. All of these evaluations will be reflected in the final report. Sincerely. 2A. a51 Lewis M. Branscomb, Director National Bureau of Standards Enclosure iv 5 FOREWORD This report concerns the relationship of measurement units to engineering standards. Although it is addressed primarily to the issues posed by Section 3 of the Metric Study Act (Public Law 90-472). it is of necessityrelated also to international standards, a subject covered by aprevious report. Reports covering other substudies of the U.S. Metric Study are listed on the inside front cover. All of these. including this report. are underevalua- tion. Hence, they are published without prejudice to the comprehensive re- port on the entire U.S. Metric Study, which will be sent tothe Congress by the Secretary of Commerce in August of 1971. This report was prepared by a Metric Study task force, headed by Dr. Robert D. Stiehler and including Mr. Gustave Shapiro. Mr. Robert J.Klein, Mr. Harry Stout). Mr. Arthur G. Strang. and Mr. Theodore R. Young.all of the National Bureau of Standards. We are grateful to Mr. Frank Masterson and Mr. R. B. Belford. President and Technical Director, respectively, of the Industrial Fasteners Institute. for permission to include their first progress report on "A Study toDevelop an Optimum Metric Fastener System." Their report.which appears as Ap- pendix V of this volume, illustrates the manner in which innovations in en- gineering standards can be achieved. In this as in all aspects of the U.S. Metric Study. the program hasbene- fited from the independent judgment and thoughtful counsel of its advisory panel and the many other organizations, groups. and committees that have participated in the Study. Daniel V. De Simone. Director U.S. Metric Study TABLE OF CONTENTS Page Letters of Transmittal iii, iv Foreword I. Executive Summary 1 2. Summary of Conclusions and Recommendations 6 3. Purpose of Standards Survey 9 4.Scope of Standards Survey 10 5. Definitions 12 6. Function of Engineering Standards 14 7.Compatibility of Standards 17 8. Development Process for Engineering Standards 18 9. Magnitude of Standardization Effort 25 10. Measuring Units in Engineering Standards 31 I I.Dimensional Specifications 34 12. Quality Specifications 43 13. Methods of Test 45 14. Descriptive Standards 47 15. I EC and Electrical Engineering Standards 48 16. ISO Recommendations 67 17. Steel 90 18. Nonferrous Metals 93 19. Plastics 96 20. Rubber 99 21..Anti-Friction Bearings 101 22.Building Construction and Materials 104 23.Pipe and Tubing 107 24.Screw Threads and Fasteners 115 25. Discussion 129 Appendices: I.Public Law 90-472 132 I I.ISO Recommendation R1000 Rules for the Use of Units of the International System of Units and a Selection of the Decimal Multiples and Submultiples of the SI Units 133 III.ASI M E380-70 Metric Practice Guide 152 IV.Compatibility of Screw Threads 187 V.First Progress Report of Industrial Fasteners Institute on a Study to Develop an Optimum Metric Fastener System 195 vi 1. EXECUTIVE SUMMARY Public Law 90 -472' approved on August 9, 1968 authorized theSecretary of Commerce to make a study to determinethe advantages and disad- vantages of increased use of the metric systemin the United States. The Congress in passing this law recognized the closerelationship between en- gineering standards and measurement units and authorized astudy to deter- mine the feasibility of retaining and promotinginternational use of dimen- sional and other engineering standards based on the customarymeasurement units of the United States. Section 3 of this act isspecifically directed to this issue and states: In conducting the studies and developing therecommendations required in this Act, the Secretary shall give full consideration tothe ad- vantages.