1、Machine Screws, Tapping Screws, and Metallic Drive Screws (Inch Series) AN AMERICAN NATIONAL STANDARD INTENTIONALLY LEFT BLANK Machine Screws, Tapping Screws, and Metallic Drive Screws (Inch Series) AN AMERICAN NATIONAL STANDARD The American Society of Mechanical Engineers Two Park Avenue New York,
2、NY 10016 USA Date of Issuance: October 11, 2013 This Standard will be revised when the Society approves the issuance of a new edition. ASME issues written replies to inquiries concerning interpretations of technical aspects of this Standard. Periodically certain actions of the ASME B18 Committee may
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5、cular code or standard. This option can be found on the appropriate Committee Page after selecting “Errata“ in the “Publication In formation“ section. ASME is the registered trademark of The American Society of Mechanical Engineers. Th is code or standard was developed under procedures accredited as
6、 meeting the criteria for American National Standards. The Standards Committee that approved the code or standard was balanced to assure that individuals from competent and concerned interests have had an opportunity to participate. The proposed code or standard was made available for public review
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8、ty of any patent rights asserted in connection w ith any items mentioned in thiis document, and does not undertake to insure anyone utilizing a standard against liability for infringement of any applicable letters patent, nor assumes any such liability. Users of a code or standard are expressly advi
9、sed that determination of the validity of any such patent rights, and the risk of infringement of such rights, is entirely their own responsibility. Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted as government or industry endorsement
10、of tlh is code or standard. ASME accepts responsibility for only those interpretations of this document issued in accordance with the established ASME procedures and policies, which precludes the issuance of interpretations by individt1als. No part of this document may be reproduced in any form, in
11、an electronic retrieval system or otherwise, without the prior written permission of the publisher. The American Society of Mechanical Engineers Two Park Avenue, New York, NY 10016-5990 Copyright 2013 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS All rights reserved Printed in U.S.A. CONTENTS Fore
12、word. . v Comntittee Roster . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii Correspondence With the B18 Committee . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13、viii Summary of Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix 1 Introductory Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
14、. . . . . 1 2 3 4 5 General Data for Machine Screw and Tapping Screw Heads . . . General Data for Machine Screws . General Data for Tapping Screws . . . . General Data for Metallic Drive Screws . . . . Figures 2 3 5 8 1 Types A, AB, B, BF, BP, and BT . . . . . . . . . . . . . . . . . . . . . . . . .
15、 . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 Types C, D, G, T, and TRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3 Type F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
16、. . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4 Typical Torsional Strength Test Fixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Tables 1 Dimensions of Slotted Flat Countersunk Head Screws . . . . . . . . . . . . . . . . . . . . . . . . .
17、 . . . . 11 2 Recess Dimensions for Flat Countersunk Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3 Dimensions of Slotted 100-deg Flat Countersunk Head Screws (Machine Screws Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
18、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4 Recess Dimensions for 100-deg Flat Countersunk Head Screws (Machine Screws Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 5 Dime
19、nsions of Slotted Close Tolerance 100-deg Flat Countersunk Head Screws (Machine Screws Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 6 Recess Dimensions for Close Tolerance 100-deg Flat Countersunk Head Screws (Machine Scre
20、ws Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 7 Dimensions of Slotted Oval Countersunk Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 8 Recess Dimensions of Oval Countersunk Head Screws . . . . .
21、. . . . . . . . . . . . . . . . . . . . . . . . 21 9 Dimensions of Slotted Undercut 82-deg Flat Countersunk Head Screws . . . . . . . . . . . . 23 10 Recess Dimensions for Undercut 82-deg Flat Countersunk Head Screws . . . . . . . . . . . . 24 11 Dimensions of Slotted Undercut Oval Countersunk Head
22、Screws . . . . . . . . . . . . . . . . . . 25 12 Recess Dimensions for Undercut Oval 82-deg Countersunk Head Screws . . . . . . . . . . . 27 13 Dimensions of Flat Countersunk Trim Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 14 Recess Dimensions for Flat Countersunk T
23、rim Head Screws . . . . . . . . . . . . . . . . . . . . . . . 29 15 Dimensions of Oval82-deg Countersunk Trim Head Screws . . . . . . . . . . . . . . . . . . . . . . . 30 16 Recess Dimensions for Ova 82-deg Countersunk Trim Head Screws . . . . . . . . . . . . . . . 33 17 Head Dimensions for Slotted
24、Pan Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 18 Dimensions of Type I Cross Recessed Pan Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 19 Recess Dimensions for Pan Head Screws (Types lA, III, and VI) . . . . . . . . . . . . . . . .
25、. . . . 36 20 Recess Dimensions for Combination Slotted-Pan Head Screws . . . . . . . . . . . . . . . . . . . . . 37 21 Dimensions of Slotted Fillister Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 22 Recess Dimensions for Fillister Head Screws . . . .
26、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 23 Dimensions of Slotted Drilled FUlister Head Screws (Machine Screws Only) . . . . . . . . 42 24 Dimensions of Slotted Truss Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 25 Rec
27、ess Dimensions for Truss Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 26 Dimensions of Combination Slotted Truss Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 27 Dimensions of Slotted Binding Head Screws (Machine Screws Onl
28、y) . . . . . . . . . . . . . . . 48 iii 28 Recess Dimensions for Binding Head Screws (Machine Screws Only) . . . . . . . . . . . . . . . 49 29 Dimensions of Plain (Unslotted) and Slotted Regular and Large Hex Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 30 Recess Dimensions for Indented Regular and Large Hex Head Screws . . . . . . . . . . . . . 52 31 Recess Dimensions for Type I Nonindented Regu lar and Large Hex Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30、. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 32 Dimensions of Plain and Slotted Hex Washer Head Screws . . . . . . . . . . . . . . . . . . . . . . . 54 33 Recess Dimensions for Indented Hex Washer Head Screws . . . . . . . . . . . . . . . . . . . . . . .
31、 56 34 Recess Dimensions for Combination Slotted Typ e I Indented Hex Washer Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 35 Dimensions of Slotted Round Head Screws . . . . . . . . . . . . . . . .
32、 . . . . . . . . . . . . . . . . . . . . . . . 58 36 Recess Dimensions for Round Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 37 Recess Dimensions for Combination Slotted Round Head Screws . . . . . . . . . . . . . . . . . . 60 38 Dimensions of Slotted R
33、ound Washer Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 39 Recess Dimensions for Round Washer Head Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 40 Dimensions of Threads and Points for Types AB and ABR Thread-Forming Tapping Screws . . . .
34、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 41 Dimensions of Threads and Points for Types Band BP Thread-Forming Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35、. . . . . . . . . . . . . . . . . 66 42 Dimensions of Threads and Points for Type A Thread-Forming Tapping Screws . . . 67 43 Dimensions of Threads and Points for Types BF and BT Thread-Cutting Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36、 . . . . . . . . . . . . . . . . . . 68 44 Dimensions of Threads and Points for Types D, F, G, and T Thread-Cutting Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 45 Dimensions of Type TRS Tapping Screws
37、 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 46 Thread Lengths for Types A, AB, B, BF, BP, and BT Tapping Screws . . . . . . . . . . . . . . . 72 47 Thread Lengths for Typ es c_ D, F, G, T, and TRS Tapping Screws . . . . . . . . . . . . . . . . . . 73 48 St
38、andard Test-Plate Thickness and Hole Sizes for Drive-Test Inspection of Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 49 Maximum D rive Torque for Type TRS Tapping Screws . . . . . . . . . . . . . . . .
39、 . . . . . . . . . . . . . 75 50 Torsional Strength Requirements for Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 51 Dimensions of Round Head Typ e U Metallic Drive Screws . . . . . . . . . . . . . . . . . . . . . . . . 76 Mandatory Appendices I Protrusion Gaging of
40、Flat Coun tersunk Heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 II Across-Corners Gaging of Hex Heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 m Gaging of Recessed Heads, Typ es I, IA, and III . . . . . . . . .
41、. . . . . . . . . . . . . . . . . . . . . . . . . . . 79 IV Wobble Gaging of Recessed Heads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 V Dimensions for No. 0000, No. 000, and No. 00 Thread Sizes . . . . . . . . . . . . . . . . . . . . . . . 88 VI
42、 Dimensions of Type C Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 VII Type VI Recess Gage Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Nonmandatory Appendices A Dimensions o
43、f Header Points for Machine Screws Before Threading . . . . . . . . . . . . . . . . 94 B Determination of Maximum Effective Design Grip Lengths . . . . . . . . . . . . . . . . . . . . . . . . 96 C Formulas for Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44、 . . . . . . . . . . . . . . . . . 98 D Approximate Hole Sizes for Tapping Screws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 E Wrench Openings for Hex Head Screws, and Square and Hex Nuts . . . . . . . . . . . . . . . . 128 iv FOREWORD American National Standards
45、 Committee B18 for the standardization of bolts, screws, nuts, rivets, and similar fasteners was organized in March 1922 as Sectional Committee 818 under the aegis of the American Engineering Standards Committee (later the Ameri.can Standards Association, then the United States of America Standards
46、Institute and, as of October 6, 1969, the American National Standards Institute, Inc.), with the Society of Automotive Engineers and the American Society of Mechanical Engineers as joint sponsors. Subcommittee 31 was subsequently established and charged with the responsibility for technical content
47、of standards covering slotted and recessed head screws. An American Standard setting forth slotted head proportions was approved and published in April1930. Over the years following the issuance of this document, the need for standards more comprehensive than head configurations became apparent. At
48、a meeting held on April14, 1942, Subcommittee 31 was reorganized and enlarged, and the following operating scope was established: The scope of Subcommittee 31 shall consist of the development and promulgation of American Standards embracing screw products variously known as machine screws, wood scre
49、ws, tapping screws, slotted head cap screws, slotted headless set screws, and machine screw nuts. The stan dards shall comprise complete product standards covering all dimensions and tolerances required for the specification and production of the products. Details shall include boundary dimensions, such as n ut width and thickness; screw head dimensions; slot and recess dimensions; body dimensions; thread classification or thread detail, as required; thread length; point design; cham fers; underhead fillets; and supporting general specifications covering the quality, finish, and
