Prevailing Torque Locknuts (Inch Series)

AN A MERICAN NA TIONAL S T AND ARD

ASME B18.16.6-2014

(Revision of ASME B18.16.6-2008)

ASME B18.16.6-2014

(Revision of ASME B18.16.6-2008)

Prevailing Torque Locknuts (Inch Series)

AN AMERICAN NA TIONAL S T AND ARD

Two Park Avenue • New York, NY • 10016 USA

Date of Issuance: April 30, 2014

This Standard will be revised when the Society approves the issuance of a new edition.

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The American Society of Mechanical Engineers Two Park Avenue, New York, NY 10016-5990

Copyright © 2014 by

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS

All rights reserved Printed in U.S.A.

CONTENTS

Foreword iv

Committee Roster v

Correspondence With the B18 Committee vi

1. Introduction 1

2. Reference Standards 1

3. Terminology 1

4. Dimensions 1

5. Nut Designs and Property Grades 1

6. Corner Fill 2

7. Chamfers and Bearing Circles 2

8. Countersinks 2

9. Threads 2

10. Material, Mechanical, and Performance Properties 11

11. Test Methods 11

12. Grades and Manufacturing Marking 15

13. Quality Assurance 15

14. Workmanship 15

15. Designation 15

Tables

1. Chemical Composition Requirements 2

2. Hardness Requirements 2

3. Style NE Nylon Insert Locknut Dimensions 3

4. Style NTE Nylon Insert Locknut Dimensions 4

5. Style NU Nylon Insert Locknut Dimensions 5

6. Style NTU Nylon Insert Locknut Dimensions 6

7. Style NM Nylon Insert Locknut Dimensions 7

8. Style NTM Nylon Insert Locknut Dimensions 7

9. Dimensions of Nylon Insert Hex Flange Nuts 8

10. Dimensions of Prevailing Torque All-Metal Type Hex Nuts 9

11. Dimensions of Prevailing Torque All-Metal Type Hex Flange Nuts 10

12. Proof Loads, Clamp Loads, and Prevailing Torques for Coarse Thread Locknuts 12

13. Proof Loads, Clamp Loads, and Prevailing Torques for Fine Thread Locknuts 13

14. Proof Loads, Clamp Loads, and Prevailing Torques for UN8 Series Thread

Locknuts 13

iii

FOREWORD

ASME B18.16.6-2008 was balloted and approved by the B18 Standards Committee and B18 Subcommittee 16 on April 29, 2008. The proposal was submitted to the American National Standards Institute and designated as an American National Standard on August 25, 2008.

At the B18 meeting in the Fall of 2011, Subcommittee 16 decided to expand this Standard to include all styles of locking nuts. B18.16.6 will now contain dimensional and performance requirements for nonmetallic insert and all-metal locking nuts in a variety of grades. This Standard is intended to replace IFI-100/107 which the Industrial Fasteners Institute has agreed to withdraw after the publication of this Standard.

This revision was approved as an American National Standard on March 12, 2014. Suggestions for improvement of this Standard are welcome. They should be sent to Secretary,

B18 Committee, The American Society of Mechanical Engineers, Two Park Avenue, New York, NY 10016-5990.

iv

ASME B18 COMMITTEE

Standardization of Bolts, Nuts, Rivets, Screws,

Washers, and Similar Fasteners

(The following is the roster of the Committee at the time of approval of this Standard.)

STANDARDS COMMITTEE OFFICERS

J. Greenslade, Chair

D. S. George, Vice Chair

W. H. King, Vice Chair

1. J. Gomez, Secretary

   
   

   
   

   V. Cartina, Nylok, LLC

2. A. Clever, Contributing Member, Consultant

A. P. Cockman, Ford Motor Co.

1. A. D. de la Garza, TSP, Inc.

2. S. George, Ramco Specialties

STANDARDS COMMITTEE PERSONNEL

D. Korneffel, Cadenas PARTsolutions

J. F. McCarrick, Defense Supply Center — Philadelphia

J. P. Nash, Caterpillar, Inc.

M. D. Prasad, Contributing Member, Global M&F Solutions, Inc.

Q. M. Smith III, Oregon Department of Transportation

C. J. Gomez, The American Society of Mechanical Engineers

J. Greenslade, Industrial Fasteners Institute

J. J. Grey, Contributing Member, Fastener Consulting Services, Inc.

A. Herskovitz, Contributing Member, Consultant

J. Hubbard, Leland-Powell Fasteners, Inc.

J. C. Jennings, Contributing Member, Naval Surface Warfare Center

W. H. King, Fastenal Co.

D. J. Soscia, General Dynamics Electric Boat Corp.

R. D. Strong, Doerken Corp.

C. B. Wackrow, MNP Corp.

W. K. Wilcox, Consultant

C. B. Williamson, Fastenal Co.

C. J. Wilson, Consultant

J. G. Zeratsky, Contributing Member, National Rivet and Manufacturing Co.

V. Cartina, Chair, Nylok, LLC

D. S. George, Vice Chair, Ramco Specialties

T. Anderson, Bay Bolt

L. C. Borowski, Greenslade & Co., Inc.

E. Chen, Super Cheng Industrial Co., Ltd.

A. P. Cockman, Ford Motor Co.

C. A. D. de la Garza, TSP, Inc.

J. E. Dutton, Allegheny Coatings

M. A. Elmi, Caterpillar, Inc.

M. C. Friel, Haydon Bolts, Inc.

J. Greenslade, Industrial Fasteners Institute

J. J. Grey, Fastener Consulting Services, Inc.

J. Hubbard, Leland-Powell Fasteners, Inc.

J. C. Jennings, Naval Surface Warfare Center

SUBCOMMITTEE 16 — NUTS

M. Kaindl, Aztech Locknut Co.

W. H. King, Fastenal Co.

J. F. McCarrick, Defense Supply Center — Philadelphia

J. Medcalf, Field Fastener

F. J. Perry, John Deere

W. L. Sakowski, Account Managers, LLC

R. M. Serabin, Freundlich Supply Co.

D. F. Sharp, GMS Structural Engineers

D. J. Soscia, General Dynamics Electric Boat Corp.

J. J. Stoczanskyj, Beacon Fasteners and Components, Inc.

R. D. Strong, Doerken Corp.

L. White, Newport News Shipbuilding

W. K. Wilcox, Consultant

C. B. Williamson, Fastenal Co.

C. J. Wilson, Consultant

v

CORRESPONDENCE WITH THE B18 COMMITTEE

General. ASME Standards are developed and maintained with the intent to represent the consensus of concerned interests. As such, users of this Standard may interact with the Committee by requesting interpretations, proposing revisions, and attending Committee meetings. Corre- spondence should be addressed to:

Secretary, B18 Standards Committee

The American Society of Mechanical Engineers Two Park Avenue

New York, NY 10016-5990

https://go.asme.org/Inquiry

Proposing Revisions. Revisions are made periodically to the Standard to incorporate changes that appear necessary or desirable, as demonstrated by the experience gained from the application of the Standard. Approved revisions will be published periodically. The Committee welcomes proposals for revisions to this Standard. Such proposals should be as specific as possible, citing the paragraph number(s), the proposed wording, and a detailed description of the reasons for the proposal, including any pertinent documentation.

Proposing a Case. Cases may be issued for the purpose of providing alternative rules when justified, to permit early implementation of an approved revision when the need is urgent, or to provide rules not covered by existing provisions. Cases are effective immediately upon ASME approval and shall be posted on the ASME Committee Web page.

Requests for Cases shall provide a Statement of Need and Background Information. The request should identify the Standard and the paragraph, figure, or table number(s), and be written as a Question and Reply in the same format as existing Cases. Requests for Cases should also indicate the applicable edition(s) of the standard to which the proposed Case applies.

Interpretations. Upon request, the B18 Standards Committee will render an interpretation of any requirement of the Standard. Interpretations can be rendered only in response to a written request sent to the Secretary of the B18 Standards Committee at go.asme.org/Inquiry.

The request for an interpretation should be clear and unambiguous. It is further recommended that the inquirer submit his/her request in the following format:

Subject: Cite the applicable paragraph number(s) and the topic of the inquiry.

Edition: Cite the applicable edition of the Standard for which the interpretation is being requested.

Question: Phrase the question as a request for an interpretation of a specific requirement suitable for general understanding and use, not as a request for an approval of a proprietary design or situation. The inquirer may also include any plans or drawings that are necessary to explain the question; however, they should not contain proprietary names or information.

Requests that are not in this format may be rewritten in the appropriate format by the Committee prior to being answered, which may inadvertently change the intent of the original request.

ASME procedures provide for reconsideration of any interpretation when or if additional information that might affect an interpretation is available. Further, persons aggrieved by an interpretation may appeal to the cognizant ASME Committee or Subcommittee. ASME does not “approve,” “certify,” “rate,” or “endorse” any item, construction, proprietary device, or activity. Attending Committee Meetings. The B18 Standards Committee regularly holds meetings and/or telephone conferences that are open to the public. Persons wishing to attend any meeting and/or telephone conference should contact the Secretary of the B18 Standards Committee. Future Committee meeting dates and locations can be found on the Committee Page at

go.asme.org/B18committee.

vi

ASME B18.16.6-2014

PREVAILING TORQUE LOCKNUTS (INCH SERIES)

1. INTRODUCTION

   1. Scope

      This Standard covers the complete general, dimen- sional, mechanical, and performance requirements (proof load, prevailing torque, and torque-tension) for carbon steel, inch series nylon insert locknuts of grades N2, N5, and N8 in styles NE (1⁄4 in. to 11⁄2 in.), NTE (1⁄4 in. to 11⁄2 in.), NU (1⁄4 in. to 3 in.), NTU (1⁄4 in. to 3 in.), NM (#2 to #12), NTM (#2 to #12), and hex flange (1⁄4 in. to 3⁄4 in.). This Standard also includes all-metal hex (#4 to 11⁄2 in.) and hex flange (1⁄4 in. to 3⁄4 in.) locking nuts of grades A, B, C, F, and G. These nut designs are designated as American National Standards.

      
      

   2. Comparison to ISO Standards

      There is no ISO inch standard for these products.

      
      

2. REFERENCE STANDARDS

   The following is a list of publications referenced in this Standard. Unless otherwise specified, the reference standard(s) shall be the most recent issue at the time of order placement.

   ASME B1.1, Unified Inch Screw Threads

   ASME B1.3, Screw Thread Gaging Systems for Acceptability: Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ)

   ASME B1.15, Unified Inch Screw Threads (UNJ Thread Form)

   ASME B18.2.1, Square, Hex, Heavy Hex, and Askew Head Bolts and Hex, Heavy Hex, Hex Flange, Lobed Head, and Lag Screws (Inch Series)

   ASME B18.12, Glossary of Terms for Mechanical Fasteners

   ASME B18.18, Quality Assurance for Fasteners

   ASME B18.21.1, Washers: Helical Spring-Lock, Tooth Lock and Plain Washers

   Publisher: The American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016-5990; Order Department: 22 Law Drive, P.O. Box 2900, Fairfield, NJ 07007-2900 (www.asme.org)

   ASTM F436, Hardened Steel Washers

   ASTM F606, Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, and Rivets

   ASTM F788, Surface Discontinuities of Bolts, Screws, and Studs, Inch and Metric Series

   ASTM F812, Surface Discontinuities of Nuts (Inch Series) ASTM F1137, Standard Specification for Phosphate/Oil

   Corrosion Protective Coatings for Fasteners

   ASTM F1470, Standard Practice for Fastener Sampling for Specified Mechanical Properties and Performance Inspection

   ASTM F1941, Electrodeposited Coatings on Threaded Fasteners [Unified Inch Screw Threads (UN/UNR)] Publisher: ASTM International, 100 Barr Harbor Drive,

   P.O. Box C700, West Conshohocken, PA 19428-2959 (www.astm.org)

   IFI-101, Torque-Tension Requirements for Prevailing- Torque Type Steel Hex and Hex Flange Nuts

   Publisher: Industrial Fasteners Institute (IFI), 6363 Oak Tree Blvd., Independence, OH 44131 (www.indfast.org)

   SAE J409, Product Analysis — Permissible Variations from Specified Chemical Analysis of a Heat or Cast of Steel

   Publisher: SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001 (www.sae.org)

   
   

3. TERMINOLOGY

   For definitions of terms relating to fasteners or compo- nent features thereof used in this Standard, refer to ASME B18.12.

   
   

4. DIMENSIONS

   Unless otherwise specified, all dimensions in this Standard are inches and shall be as specified in the tables and sections 6 through 9. All dimensions apply before coating.

   
   

5. NUT DESIGNS AND PROPERTY GRADES

   1. Nylon Insert Locknuts

Nylon insert locknuts are two-piece construction hex nuts and hex flange nuts that derive their prevailing

1