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0759b70 0525492 582 m
AN AMERI CAN NATIONAL STANDARD
Screw Threads - Standard Practice for
Calculating and Rounding Dimensions
ASME B I .30M-1992
The American Society of Mechanical Engineers
345 East 47th Street, New York, N.Y. 10017 -
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ASME B1.30M 92 m 0759670 0525493 419 m
Date of Issuance: September 15, 1992
This Standard will be revised when the Society approves the issuance of a new edition. There will be no addenda or written interpretations of the re- quirements of this Standard issued to this Edition.
ASME is the registered trademark of The American Society of Mechanical Engineers.
This code or standard was developed under procedures accredited as meeting the criteria for American National Standards. The Consensus 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 and comment which provides an opportunity for additional public input from industry, academia, regulatory agencies, and the public-at-large.
ASME does not "approve," "rate," or "endorse" any item, construction, proprietary device, or activity.
ASME does not take any position with respect to the validity of any patent rights asserted in connection with any items mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability for infringement of any applicable Letters Patent, nor assume any such liability. Users of a code or standard are expressly advised 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 of this code or standard.
ASME accepts responsibility for only those interpretations issued in accordance with governing ASME procedures and policies which preclude the issuance of interpretations by individual volunteers.
No part of this document may be reproduced in any form, in an electronic retrieval system or otherwise,
without the prior written permission of the publisher.
Copyright O 1992 by THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS
AI1 Rights Reserved Printed in U.S.A.
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ASME BL-30M 92 W O759670 O525494 355 W
FOREWORD
(This Foreword is not part of ASME B1.30M-1992.)
The American National Standards Committee B1 for standardization of screw threads was organized in 1920 as sectional committee B1 under the sponsorship of the American Engi- neering Standards Committee (later the American Standards Association, then the United States of America Standards Institute and as of October 6, 1969, the American National Standards Institute, Inc.), with the Society of Automotive Engineers and The American Society of Me- chanical Engineers as joint sponsors. As a result, a great deal of effort was expended through the years toward development of several screw thread standards.
Recognizing the need to standardize the method of rounding decimal values in the calcu- lation of screw thread dimensions, the ASME Standards Committee B1 charged Subcommittee 30 with the responsibility for producing such a standard.
This Standard designated ASME B l . 30M was developed to serve as the basis for rounding of decimal values associated with the computation of screw thread dimensions.
The examples and formulas depicted within this Standard are for reference only and are presented only to clarify the rounding procedures described. When calculating the different thread characteristics for a particular thread form, refer to the appropriate ASME B 1 standard for the formulas and methodology of calculation for that thread.
Suggestions for improvement of this Standard will be welcome. They should be sent to Secretary, ASME B1 Main Committee, 345 East 47th Street, New York, NY 10017.
This Standard was approved as an American National Standard on June 29, 1992.
111 ...
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o
ASME Bl1.30M 92 m 0759670 0525495 291 m
ASME STANDARDS COMMITTEE B I Standardization and Unification of Screw Threads
(The following is the roster of the Committee at the time of approval of this Standard.)
OFFICERS
E. Schwartz, Chairman K. E. McCullough, Vice Chairman
C . J. Gomez, Secretary
COMMITTEE PERSONNEL
J. R. Anderson R. J. Browning R. M. Byrne D. P. Cadieux F. G. Calderone F. H. Cantrell R. S. Chamerda R. Dodge P. H. Drake A. E. Ellis H. W. Ellison C. G. Erickson W. C. Farrell, Jr. R. E. Ferry, Jr. G. A. Flannery D. S. George J. Greenslade J. O. Heinze R. R. Hyman C. W. Jatho S. P. Johnson S. I. Kanter J. Krippes
R. W. Lamport R. S. LaNier J. B. Levy J. C. McMurray D. Miskinis W. R. Newman A. Painter G. A. Russ R. J. Sabatos D. M. Satava M. M. Schuster R. H. Searr R. E. Seppey A. D. Shepherd, Jr. V. B. Shook A. G. Strang J. F. Sullivan R. L. Tennis A. F. Thibodeau A. M. Wilkerson C. J. Wilson
F. H. Cantrell, Chairman R. J. Browning D. P. Cadieux R. S . Chamerda P. H. Drake R. E. Ferry, Jr.
V
T. L. Gaslin D. S. George D. M. Satava E. Schwartz R. H. Searr C. J. Wilson.
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A S I E BL.30M 72 0759b70 05251t7b L28
CONTENTS
... Foreword . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Standards Committee Roster v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Metric Application 1
2 Rounding of Decimal Values 1 2.1 RoundingPolicy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 Calculations From Formulas 2 3.1 General Rules 2 3.2 Examples 3
3.2.1 Inch Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3.2.2 Metric Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3.2.3 Metric External Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3.2.4 Metric Internal Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Thread Form Constants 1 1
Appendix A Thread Form Tables 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tables 1 Thread Data. UN. UNR. and UNJ Profiles (Inch Screw Threads) . . . . . . . . . . . . . . . . . . . . . . . . 14 2 Thread Data. UN. UNR. and UNJ Profiles (Inch Screw Threads). ....................... 16 3 Thread Data. M and MJ Profiles (Metric Screw Threads) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
vii
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ASME BL.30M 92 m O759670 0525497 Ob4 m
ASME B1.30M-1992
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS
1 GENERAL
1.1 Purpose
The purpose of this Standard is to establish uniform practices for calculating and rounding the numeric values used for inch and metric screw thread design data dimensions. No attempt is made to establish a policy of rounding actual thread characteristics measured by the man- ufacturer or user of thread gages. Covered is the Standard Rounding Policy regarding the last figure or decimal place to be retained by a numeric value and the number of decimal places to be retained by values used in intermediate calculations of thread dimensions. Some values listed in the Appendix may differ by as much as 0.O001 in. or 0.001 mm from values shown in previous issues of ASME B1 thread standards and are to take precedence in all future ASME B1 Standards.
1.2 Metric Application
Allowances (fundamental deviations) and tolerances for metric M and MJ screw threads are based upon formulas which appear in applicable standards. Values of allowances for standard tolerance positions and values of tolerances for standard tolerance grades are tabulated in these standards for a selection of pitches. Rounding rules specified below have not been applied to these values but have followed practices of the International Organization for Standardization (ISO). For pitches which are not included in the tables, standard formulas and the rounding rules specified herein are applicable.
2 ROUNDING OF DECIMAL VALUES
The following rounding practice represents the method to be used in all future ASME B1 thread standards.
NOTE: It is recognized that this Standard is not in agreement with other published documents, e.g., ASME SI-9, Guide for Metrication of Codes and Standards SI (Metric) Units, and ASTM E 380, Standard for Metric Practice. The rounding practices used in the forenamed documents are designed to produce even distribution of numerical values. The purpose of this document is to define the most practical and common used method of rounding numerical thread form values. Considering today’s technology, application of this method is far more practical in the rounding of thread form values.
2.1 Rounding Policy
2.1 .I When the figure next beyond the last figure or place retained is less than 5 , the figure in the last place retained is kept unchanged.
EXAMPLE
1 .O12342 1.01234 1 .O12342 1 .O123 1.012342 1 .o12
1
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ASME B l . 3 0 1 72 0757b70 0525498 T T 0 m
SCREW THREADS - STANDARD PRACTICE FOR ASME B1.30M-1992 CALCULATING AND ROUNDING DIMENSIONS
2.1.2 When the figure next beyond the last figure or place retained is greater than 5, the figure in the last place retained is increased by l .
EXAMPLE
1.56789 1 S679 1.56789 1.568 1.56789 1.57
2.1.3 When the figure next beyond the last figure or place retained is 5 , and: (a) there are no figures, or only zeros, beyond this 5, the last figure should be increased
by 1
EXAMPLE
1.01235 1.0124 1 .O123500 1 .O124 1 .O12345 1.01235 l . O 1234500 1.01235
(b) if the 5 next beyond the figure in the last place to be retained is followed by any figures other than zero, the figure in the last place retained should be increased by 1
EXAMPLE
1.0123501 1 .O124 1.0123599 1.0124 1.01234501 1 .O1235 1 .O1234599 1 .O1235
2.1.4 The final rounded value is obtained from the most precise value available and not from a series of successive roundings. For example, 0.5499 should be rounded to 0.550, 0.55 and 0.5 (not 0.6), since the most precise value available is less than 0.55. Similarly, 0.5501 should be rounded as 0.550, 0.55 and 0.6, since the most precise value available is more than 0.55. In the case of 0.5500 rounding should be 0.550, 0.55 and 0.6, since the most precise value available is 0.5500.
3 CALCULATIONS FROM FORMULAS
3. I General Rules
3.1 .I Values used in intermediate calculations are rounded to two places beyond the num- ber of decimal places retained for the final value.
3.1.2 Rounding to the final value is the last step in a calculation.
3.1.3 For inch screw thread dimensions, four decimal places are required for the final values of pitch diameter, major diameter, and minor diameter with the exception of Class 1B and 2B internal thread minor diameters for thread sizes O. 138 and larger, see below. The final values for the allowance and tolerances applied to thread elements are expressed to four dec- imal places.
(a) Minor Diameter Exceptions for Internal í%reads: ( I ) Minimum Minor Diameter, all classes are calculated and then rounded off to the
2
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ASME BLm30fl 92 m 0759b70 0525499 937 W
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS ASME B1.30M-1992
nearest 0.001 in. and expressed in three decimal places for sizes 0.138 in. and larger. For Class 3B, a zero is added to yield four decimal places.
(2) Maximum Minor Diameter, all classes are calculated before rounding, then rounded for Classes 1B and 2B to the nearest 0.001 in. for sizes O. 138 in. and larger. Class 3B values are rounded to four decimal places.
3.1.4 Metric screw threads are dimensioned in millimeters. The final values of pitch di- ameter, major diameter, minor diameter, allowance and thread element tolerances are ex- pressed to three decimal places.
3.2 Examples
The formulas in the examples are based on those listed in ASME B l . 1, Unified Inch Screw Threads, for para. 3.2.1, and ANSUASME B1.13M, Metric Screw Threads - M Profile, for para. 3.2.2. The constant values may differ in the number of decimal places shown to conform to this Standard's policy of rounding numeric values and number of decimal places to be retained.
3.2.1 Inch Screw Threads (all dimensions expressed in inches)
Thread Size = 0.5000-28 UNEF-2ARB For calculations below; P = l /n = 1/28 = 0.03571429
(u) Maximum major diameter = Basic major diameter - allowance
d rnax = d bsc - l e s \
d bsc = 0.5000
es = 0.300 Td, (2A)
= 0.300 (0.003668)
= 0.001100
= 0.0011
This is the final value of the basic ma- jor diameter which is expressed in four decimal places.
[Class 2A Pitch Diameter Tolerance see para. 3.2.l(d)]
The six place value for Class 2A Pitch Diameter tolerance is used in this cal- culation.
This figure is rounded to four decimal places to obtain the final value of es.
d max = 0.5000 - 0.001 1 = 0.4989
(b) d min (Minimum External Thread Major Diameter)
= d max - Td (Major diameter tolerance)
Td = 0.060
= 0.060 7(0.03571429)*
3
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ASME BI .30M-1992
= 0.060 X 0.108450
= 0.006507
= 0.0065
d min = 0.4989 - 0.0065 = 0.4924
(c) d2 max (Maximum Pitch Diameter)
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS
This figure is rounded to obtain the final value of Td
= d max - 0.64951905P
= 0.4989 - 0.64951905 (0.03571429)
= 0.475703 This figure is rounded to obtain the final value of d2 max
= 0.4757
( d ) d2 min (Minimum Pitch Diameter)
= d2 max - Td, (External Pitch Diameter Tolerance)
Td2 = 0.0015 G + 0.0015 JLE (Length of Engagement) + 0.015
= 0.0015 'm + 0.0015 h Ï % + 0.015 ?(0.03571429)2
= 0.0015 'm + 0.0015 + 0.015 'Jon276 = 0.001191 + 0.000850 + 0.001627
= 0.003668
= 0.0037
d2 min = 0.4757 - 0.0037 = 0.4720
(e) d3 max (Maximum Minor Diameter) UNR
= d max - 1.19078493P
= 0.4989 - 1.19078493 (0.03571429)
= 0.4989 - 0.042528
= 0.456372
= 0.4564
4
This figure is rounded to obtain the final value of Td,
This figure is rounded to obtain the final value of d3 max.
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ASME B3.30M 92 m O759670 0525503 335 m
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS
( f ) D, min (Minimum Internal Minor Diameter)
= D bsc (Basic Major Diameter) - 1.08253175P
= 0.5000 - 1.08253175 (0.03571429)
= 0.5000 - 0.038662
= 0.461338
= 0.461
(8) D, max (Maximum Internal Minor Diameter)
= D I min + TD, (Internal Minor Diameter)
í V I = 0.25P - 0.4P2
= 0.25 (0.03571429) - 0.40 (0.00127551)
= 0.008929 - 0.000511
= 0.008418
D, max = 0.461338 + 0.008418 = 0.469756
D, max = 0.470
ASME B1.30M-1992
For the Class 2B thread used in our example this figure is rounded to three decimal places to obtain the final value ofD, min
This figure is rounded to three decimal places to obtain the final value of T D ,
3.2.2 Metric Screw Threads (all dimensions expressed in millimeters)
Thread Size = M12 X 1.75 - 4g6g
(u) Maximum major diameter = Basic major diameter - allowance
dmax = dbsc - ( e s (
d bsc = 12.000
es = 0.034 (tabulated value)
d max = 12.000 - 0.034 = 11.966
= 11.966 when rounded
(6) Minimum major diameter = Maximum major diameter - tolerance
d min = d max - Td
5
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I ASME Bl1.30M 92 m 0759b70 O525502 251 D
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS ASME B1.30M-1992
d max = 11.966 [see para. 3.2.2(a)]
Td = 0.265 (tabulated value)
d min = 11.966 - 0.265 = 11.701
= 11.701 when rounded.
(c) Maximum pitch diameter = Basic major diameter - allowance - 0.64951905P
dz max = d max - 0.6495 1905P
d max = 11.966 [see para. 3.2.2(a)]
dz max = 11.966 - 1.136658 = 10.829342
= 10.829 when rounded
(d) Minimum pitch diameter = Maximum pitch diameter - tolerance
d2 min = d2 max - Td,
dz max = 10.829 [see para. 3.2.2(c)J
Td2 = 0.095 (tabulated value)
d2 min = 10.829 - 0.095 = 10.734
= 10.734 when rounded
(e) Maximum minor diameter (flat form) = Maximum pitch diameter - 0.43301270P
dl max = d2 max - 0.43301270P
d2 max = 10.829 [see para. 3.2.2(c)]
d, max = 10.829 - 0.757773 = 10.071227
= 10.071 when rounded
(f) Minimum minor diameter (round form) = Minimum pitch diameter - 0.61602540P
d3 min = d2 min - 0.61602540P
d2 min = 10.734 [see para. 3.2.2(d)]
d3 min = 10.734 - 1.07804 = 9.65596
= 9.656 when rounded
6
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SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS
3.2.3 Metric External Screw Thread, MI3 x 0.9 - 4g6g (u) Maximum major diameter = Basic major diameter - allowance
d max = d bsc - I es 1 ; 1 es 1 is absolute value.
ASME EI .30M-1992
d bsc = 13.000
1 esgl = 0.015 + 0.011P
= 0.015 + 0.011 (0.9)
= 0.0249
This is the final value of the basic ma- jor diameter and is therefore expressed with 3 decimal places.
es for tolerance position “g” is not tabulated for P = 0.9 so it must be calculated.
This figure is rounded to 3 decimal places to obtain the final absolute value of allowance for tolerance po- sition “g”.
= 0.025 When rounded
d max = 13.000 - 0.025 = 12.975
(b) Minimum major diameter = Maximum major diameter - tolerance
d min = d max - tolerance
d max = 12.975 [see para. 3.2.3(a)]
Td(6) = 0.18 3@ - - 0.00315 &
0.00315 = O. 18 (0:9)2/3 - ~
(0.9)”’
0.00315 0.94868
= 0.18 (0.93217) - ____
= 0.16447
= O. 164 when rounded
d min = 12.975 - 0.164 = 12.811
Td for tolerance grade 6 is not tabu- lated for P = 0.9, it must be calcu- lated
This figure is rounded to 3 decimal places to obtain final value of major diameter tolerance for tolerance grade 6.
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ASME BL-30M 92 m 0759670 0525504 O24 m
SCREW THREADS - STANDARD PRACTICE FOR ASME B1.30M-1992 CALCULATING AND ROUNDING DIMENSIONS
(c) Maximum pitch diameter = (Basic major diameter - allowance) - 0.64951905P
d2 max = d max - 0.64951905P
d max = 12.975 [see para. 3.2.3(a)]
dz max = 12.975 - 0.64951905 (0.9)
= 12.39043 This figure is rounded to obtain the final value of d2 max.
= 12.390 when rounded
( d ) Minimum pitch diameter = Maximum pitch diameter - tolerance
dz min = d2 max - Td2
dz max = 12.390 [see para. 3.2.3(c)]
Td2 (4) = 0.63 Td2 (6) Td2 for tolerance grade 4 (or 6) is not tabulated for P = 0.9 so it must be calculated.
= 0.63 [0.09 P0.4do.']
= 0.63 E0.09 (0.9)o.4(13)o.']
= 0.63 10.09 (0.95873)( 1.29239)]
= 0.07025 This figure is rounded to 3 decimal places to obtain the final value of pitch diameter tolerance for tolerance grade 4.
= 0.070 when rounded
d2 min = 12.390 - 0.070 = 12.320
(e) Maximum minor diameter (flat form) = Maximum pitch diameter - 0.43301270P
dl max = d2 max - 0.43301270P
d2 max = 12.390 [see para. 3.2.3(c)]
dl max = 12.390 - 0.43301270 (0.9)
= 12.390 - 0.38971
= 12.00029 This figure is rounded to 3 decimal places to obtain the final value of max minor diameter
= 12.000 when rounded
8
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ASME BL.30M 92 m 0759670 0525505 Tb0 I
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS ASME B1.30M-1992
(f) For reference: Minimum minor diameter (round form) = Minimum pitch diameter - 0.61602540P
d3 min = d2 min - 0.61602540P
d, min = 12.320 [see para. 3.2.3(d)]
d3 min = 12.320 - 0.61602540 (0.9)
= 12.320 - 0.55442
= 11.76558 This figure is rounded to obtain the fi- nal value of minimum minor diameter
= l1.766 when rounded
3.2.4 Metric Internal Screw Thread, M13 x 0.9 - 6H
(u) Minimum major diameter = Basic major diameter + allowance
D min = D bsc + EI
D bsc = d bsc = 13.000 [see para. 3.2.3(a)]
EI, = O
D min = 13.000
(b) Minimum pitch diameter = Basic major diameter - 0.64951905P + allowance
D2 min = D bsc - 0.64951905P + EI
D bsc = 13.000 [see para. 3.2.4(a)]
EI, = O
D2 min = 13.000 - 0.64951905 (0.9) + O
= 13.000 - 0.58457
= 12.41543
= 12.415 when rounded
This figure is rounded to obtain the fi- nal value of minimum pitch diameter.
(c) Maximum pitch diameter = Minimum pitch diameter + tolerance
D2 max = D2 min + T D 2
D2 min = 12.415 [see para. 3.2.4(b)]
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ASME B1.30M-1992
T D 2 (6) = 1.32 TG$ (6)
ASME BL-30M 92 m 0759b70 0525506 7T7 m
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS
í ' D 2 (or TD,) for tolerance grade 6 is not tabulated for P = 0.9 so it must be calculated
= 1.32 [0.09 P0.4do.1]
= 1.32 [0.09 (0.9)0.4(13)0.']
= 1.32 [0.09 (0.95873)(1.29239)]
= 0.14720
= 0.147 when rounded
D, max = 12.415 + 0.147 = 12.562
This figure is rounded to 3 decimal places to obtain the final value of pitch diameter tolerance for tolerance grade 6.
(d ) Minimum minor diameter = Minimum major diameter - 1.08253175P
D , min = D min - 1.08253175P
D min = 13.000 [see para. 3.2.4(a)]
D , min = 13.000 - 1.08253175 (0.9)
= 13.000 - 0.97428
This figure is rounded to 3 decimal places to obtain the final value of min- imum pitch diameter.
= 12.026 when rounded
(e) Maximum minor diameter = Minimum minor diameter + tolerance
D , max = D, min + tolerance
D, min = 12.026 [see para. 3.2.4(d)J
P = 0.9 is not tabulated nor is there any IS0 formula applicable to this pitch. Therefore, a tolerance midway between the tabulated values for P = 0.8 and P = 1.0 has been selected. This value is T D , (6) = 0.218
D , max = 12.026 + 0.218 = 12.244
(f) For reference: Maximum major diameter = Maximum pitch diameter + 0.79385662P
10
Copyright ASME International Provided by IHS under license with ASME
Not for ResaleNo reproduction or networking permitted without license from IHS
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ASME BL-30M 92 m 0759b70 0525507 833 m
SCREW THREADS - STANDARD PRACTICE FOR CALCULATING AND ROUNDING DIMENSIONS
D max = D2 max + 0.79385662P
D2 max = 12.562 [see para. 3.2.4(c)]
D max = 12.562 + 0.79385662 (0.9)
= 12.562 + 0.71447
= 13.27647
ASME B1.3OM-1992
This figure is rounded to 3 decimal places to obtain the final value of max- imum major diameter
= 13.276 when rounded
4 THREAD FORM CONSTANTS’
Thread Form Data Tables. The number of decimal places and the manner in which they are listed should be consistent. Thread form constants printed in older thread standards are based on a function of thread height (H) or pitch (P) . The equivalent of the corresponding function is also listed. There are some constants that would require these values to 8 decimal places before they would round to equivalent values. For standardization the tabulated listing of thread values based on a function of pitch has been established, with thread height used as a reference only. All thread calculations are to be perforded using a function of pitch ( P ) , rounded to 8 decimal places, not a function of thread height (m. Thread height is to be used for reference only.
r
I
l
Constant
0.0481 1 2 5 2 ~
0 .08660254~
0.1 oa2531 ap 0 . 1 2 9 9 0 3 a 1 ~
0.05412659P
0.09622504P
0.14433757P 0.1 6237976P 0.21650635P
0.2886751 3~
0 .360a4392~ 0 . 3 9 6 9 2 8 3 1 ~
0.32475953P
0.43301 270P 0.48713929P 0.541 26588P 0.57735027P O. 59539247P
0.61 343466P 0.61602540P 0.64951 905P 0 .7216a783~ 0 . 7 9 3 a 5 6 6 2 ~ 0.86602540P 1.082531 75P 1 .1 9Q78493P 1 . 2 2 6 a 6 9 3 2 ~
I l Reference Values
Hl1 8 Hl1 6 HI1 O Hl9 Hl8
3H120 Hl 6
3Hl16 Hl4
H13 3 Hl8 5Hl12
1 1 Hl24 Hl 2
9Hl16 5Hl8 2 Hl3
l l H l 1 6
17Hl24 . . .
3 Hl4 5H/16
l l H / 1 2 H
5 Hl4 1 1 Hl% 17Hl12
11
0.0556H 0.0625H O. 1 OOOH 0.1111H O. 1250H O. 1 500H O. 1667H o. 1 8 7 5 ~ 0.2500H
0.3333H 0.3750H 0.41 67H 0 . 4 5 8 3 ~ 0.5000H 0.5625H 0.6250H 0.6667H 0 . 6 8 7 5 ~
0 . 7 0 8 3 ~ 0.71 13H 0.7500H 0.8333H 0.9167H 1.0000H 1.2500H 1.3750H 1.41 67H
Copyright ASME International Provided by IHS under license with ASME
Not for ResaleNo reproduction or networking permitted without license from IHS
--``-`-`,,`,,`,`,,`---
ASME B1.30M 92 0759b70 0525508 77T m
APPENDIX A THREAD FORM TABLES
(This Appendix is not part of ASME B1.30M-1992 and is included for information only.)
Tables 1 through 3 have many of the common values listed for 60 deg. in. and metric threads. Tables 1 and 3 were calculated using pitch (P) as a function of thread height (H) . Table 2 values are based on pitch ( P ) alone.
13
Copyright ASME International Provided by IHS under license with ASME
Not for ResaleNo reproduction or networking permitted without license from IHS
--``-`-`,,`,,`,`,,`---
TABL
E 1
THR
EAD
D
ATA,
U
N,
UN
R,
AND
U
NJ
PRO
FILE
S (IN
CH
SC
REW
TH
REA
DS)
Refer
ence
On
ly )
HI’16
TPI
Pitch
, P
0.05
4126
59f
1 2
3
IO
0.01
2500
00
0.00
0677
‘2
0.01
3888
89
0.00
0752
i4
0.01
5625
00
0.00
0846
i6
0.01
7857
14
0.00
0967
.8
0.02
0833
33
0.00
1128
.4
0.02
2727
27
0.00
1230
.d
0.02
5000
00
0.00
1353
i6
0.02
7777
78
0.00
1504
12
0.
0312
5000
0.
0016
91
8 0.
0357
1429
0.
0019
33
:7 0.
0370
3704
0.
0020
05
4 0.
0416
6667
0.
0022
55
.O
0.05
0000
00
0.00
2708
8
0.05
5555
56
0.00
3007
6
O.Of
j2500
00
0.00
3383
4
0.07
1428
57
0.00
3866
3
0.07
6923
08
0.00
4164
2
0.08
3333
33
0.00
4511
1.5
0.
0869
5652
0.
0047
07
1 0.
0909
0909
0.
0049
21
0 0.
1000
0000
0.
0054
13
9 0.
1111
1111
0.
0060
14
8 0.
1250
0000
0.
0067
66
7 0.
1428
5714
0.
0077
32
6 0.
1666
6867
0.
0090
21
5 0.
2000
0000
0.
0108
25
4.5
0.22
2222
22
0.01
2028
4
0.25
0000
00
0.01
3532
Hi10
Hi
8 3H
i20
I.086
6025
41
L108
2531
8r
I.129
9038
11
4 5
6
0.00
1083
0.
0013
53
0.00
1624
0.
0012
03
0.00
1504
0.
0018
04
0.00
1353
0.
0016
91
0.00
2030
0.
0015
46
0.00
1933
0.
0023
20
0.00
1804
0.
0022
55
0.00
2706
0.
0019
68
0.00
2460
0.
0029
52
0.00
2165
0.
0027
06
0.00
3248
0.
0024
06
0.00
3007
0.
0036
08
0.00
2706
0.
0033
83
0.00
4059
0.
0030
93
0.00
3866
0.
0046
39
0.00
3208
0.
0040
09
0.00
4811
0.
0036
08
0.00
45
11
0.00
5413
0.
0043
30
0.00
5413
0.
0064
95
0.00
48
11
0.00
6014
0.
0072
17
0.00
5413
0.
0067
66
0.00
8119
0.
0061
86
0.00
7732
0.
0092
79
0.00
6662
0.
0083
27
0.00
9993
0.
0072
17
0.00
9021
0.
0108
25
0.00
7531
0.
0094
13
0.01
1296
0.
0078
73
0.00
9841
0.
0118
09
0.00
8660
0.
0108
25
0.01
2990
0.
0096
23
0.01
2028
0.
0144
34
0.01
0825
0.
0135
32
0.01
6238
0.
0123
72
0.01
5465
0.
0185
58
0.01
4434
0.
0180
42
0.02
1651
0.
0173
21
0.02
1651
0.
0259
81
0.01
9245
0.
0240
56
0.02
8868
0.
0216
51
0.02
7063
0.
0324
76
HI6 7
0.00
1804
0.
0020
05
0.00
2255
0.
0025
77
0.00
3007
0.
0032
80
0.00
3608
0.
0040
09
0.00
45
11
0.00
5155
0.
0053
46
0.00
6014
0.
0072
17
0.00
8019
0.
0090
2 1
0.01
0310
0.
0111
03
0.01
2028
0.
0125
51
0.01
3122
0.
0144
34
0.01
6038
0.
0180
42
0.02
0620
0.
0240
56
0.02
8868
0.
0320
75
0.03
6084
PC
3Hll6
I. 16
2379
761
8
0.00
2030
0.
0022
55
0.00
2537
0.
0029
00
0.00
3383
0.
0036
90
0.00
4059
0.
0045
11
0.00
5074
0.
0057
99
0.00
6014
0.
0067
66
0.00
8119
0.
0090
21
0.01
0149
0.
0115
99
0.01
2491
0.
0135
32
0.01
4120
0.
0147
62
0.01
6238
0.
0180
42
0.02
0297
0.
0231
97
0.02
7063
0.
0324
76
0.03
6084
0.
0405
95
HI4
b.21
6506
351
9 .
0.00
2706
0.
0030
07
0.00
3383
0.
0038
66
0.00
4511
0.
0049
21
0.00
5413
0.
0060
14
0.00
6766
0.
0077
32
0.00
8019
0.
0090
21
0.01
0825
0.
0120
28
0.01
3532
0.
0154
65
0.01
6654
0.
0180
42
0.01
8827
0.
0196
82
0.02
1651
0.
0240
56
0.02
7063
0.
0309
29
0.03
6084
0.
0433
01
0.04
8113
0.
0541
27
PC
HI3
I.288
6751
31
10
0.00
3608
0.
0040
09
0.00
4511
0.
0051
55
0.00
6014
0.
0065
61
0.00
7217
0.
0080
19
0.00
9021
0.
0103
10
0.01
0692
0.
0120
28
0.01
4434
0.
0160
38
0.01
8042
0.
0206
20
0.02
2206
0.
0240
56
0.02
5102
0.
0262
43
0.02
8868
0.
0320
75
0.03
6084
0.
0412
39
0.04
8 11
3 0.
0577
35
0.06
4150
0.
0721
69
3Hi8
1.32
4759
531
11
0.00
4059
0.
0045
11
0.00
5074
0.
0057
99
0.00
6766
0.
0073
81
0.00
8119
0.
0090
21
0.01
0149
0.
0115
99
0.01
2028
0.
0135
32
0.01
6238
0.
0180
42
0.02
0297
0.
0231
97
0.02
4982
0.
0270
63
0.02
8240
0.
0295
24
0.03
2476
0.
0360
84
0.04
0595
0.
0463
94
0.05
4127
0.
0649
52
0.07
2169
’ 0.
0811
90
HI2
I.433
01
2701
12
0.00
5413
0.
0060
14
0.00
6766
0.
0077
32
0.00
902
1 0.
0098
41
0.01
0825
0.
0120
28
0.01
3532
0.
0154
65
0.01
6038
0.
0180
42
0.02
1651
0.
0240
56
0.02
7063
0.
0309
29
0.03
3309
0.
0360
84
0.03
7653
0.
0393
65
0.04
3301
0.
0481
13
0.
0541
27
0.06
1859
0.
0721
69
0.08
6603
0.
0962
25
0.10
8253
(Con
tinue
d)
Cop
yrig
ht A
SM
E In
tern
atio
nal
Pro
vide
d by
IHS
und
er li
cens
e w
ith A
SM
EN
ot fo
r R
esal
eN
o re
prod
uctio
n or
net
wor
king
per
mitt
ed w
ithou
t lic
ense
from
IHS
--``-`-`,,`,,`,`,,`---
I- r
o r-
m r
15
Copyright ASME International Provided by IHS under license with ASME
Not for ResaleNo reproduction or networking permitted without license from IHS
--``-`-`,,`,,`,`,,`---
~ m m w m m ~ m m r b b o a o m ~ m a - o - o a b o ~ o m m a m m ~ o ~ ~ ~ o m o m ~ ~ m r n ~ m o - o m w o ~ o
- - - - ~ ~ ~ ~ n m m b m m w ~ ~ m m m ~ ~ - - - ~ ~ ~ ~ m m ~ o ~ m ~ - m ~ - o m ~ - a m w o o - ~ ~ w o ~ o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
J
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
16
Copyright ASME International Provided by IHS under license with ASME
Not for ResaleNo reproduction or networking permitted without license from IHS
--``-`-`,,`,,`,`,,`---
ASME B1-30M 92 O759670 0525532 3TO W
u!
n
p / a
c I
II
Ir
m
(u
o o o o ö ö d d d ö ö o ~ d d d d d d d d d d ò o o o o o o o o o o o o c
17
Copyright ASME International Provided by IHS under license with ASME
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--``-`-`,,`,,`,`,,`---
Ref
) 9H
i16
5Hl8
2Hl3
11H1
16
3Hl4
llH11
2 H
5H14
llH
l8
Pitch
3.
4871
3929
P 3.
5412
6566
P 0.
5773
5027
P 0.
5953
9247
P ( 1
.6160
254O
P ’
( 1.6
4951
905P
D.
7938
5662
P 1.8
6602
54OP
I .
0825
3175
P 1.
1907
8493
P
1 12
13
14
15
16
17
18
19
20
21
0.20
0.09
7428
0.
1082
53
0.11
5470
0.
1190
78
0.12
3205
0.
1299
04
0.15
8771
0.
1732
05
0.25
0.12
1785
0.
1353
16
0.14
4338
0.
1488
48
0.15
4006
0.
1623
80
0.19
8464
0.
2165
06
0.30
0.14
6142
0.
1623
80
0.17
3205
0.
1786
18
0.18
4808
0.
1948
56
0.23
8157
0.
2598
08
0.35
0.17
0499
0.
i a94
43
0.20
2073
0.
2083
87
0.21
5609
0.
2273
32
0.27
7850
0.
3031
09
0.40
0.19
4856
0.
2165
06
0.23
0940
0.
2381
57
0.24
6410
0.
2598
08
0.31
7543
0.
3464
10
0.45
0.21
9213
0.
2435
70
0.25
9808
0.
2679
27
0.27
7211
0.
2922
84
0.35
7235
0.
3897
11
0.50
0.24
3570
0.
2706
33
0.28
8675
0.
2976
96
0.30
8013
0.
3247
60
0.39
6928
0.
4330
13
0.60
0.29
2284
0.
3247
60
0.34
6410
0.
3572
35
0.36
9615
0.
3897
1 i
0.47
6314
0.
5196
15
0.70
0.34
0998
0.
3788
86
0.40
4145
0.
4167
75
0.43
1218
0.
4546
63
0.55
5700
0.
6062
18
0.75
0.36
5354
0.
4059
49
0.43
3013
0.
4465
44
0.46
2019
0.
4871
39
0.59
5392
0.
6495
19
0.80
0.38
971
I 0.
4330
13
0.46
1880
0.
4763
14
0.49
2820
0.
5196
15
0.63
5085
0.
6928
20
1.00
0.48
7139
0.
5412
66
0.57
7350
0.
5953
92
0.61
6025
0.
6495
19
0.79
3857
0.
8660
25
1.25
0.60
8924
0.
6765
82
0.72
1688
0.
7442
41
0.77
0032
0.
8118
99
0.99
2321
1.
0825
32
1.50
0.73
0709
0.
8118
99
0.86
6025
0.
8930
89
0.92
4038
0.
9742
79
1.19
0785
1.
2990
38
1.75
0.85
2494
0.
9472
15
1.01
0363
1.
0419
37
1.07
8044
1.
1366
58
1.38
9249
1.
5155
44
2.00
0.97
4279
1.
0825
32
1.15
4701
1.
1907
85
1.23
2051
1.
2990
38
1.58
7713
1.
7320
51
2.50
1.21
7848
1.
3531
65
1.44
3376
1.
4884
81
1.54
0064
1.
6237
98
1.98
4642
2.
1650
64
3.00
1.46
1418
1.
6237
98
1.73
2051
1.
7861
77
1.84
8076
1.
9485
57
2.38
1570
2.
5980
76
3.50
I, 70
4988
1.
8944
31
2.02
0726
2.
0838
74
2.15
6089
2.
2733
17
2.77
8498
3.
0310
89
4.00
i .94
8557
2.
1650
64
2.30
9401
2.
3815
70
2.46
4102
2.
5980
76
3.17
5426
3.
4641
02
4.50
2.19
2127
2.
4356
96
2.59
8076
2.
6792
66
2.77
2114
2.
9228
36
3.57
2355
3.
8971
14
5.00
2.43
5696
2.
7063
29
2.88
6751
2.
9769
62
3.08
0127
3.
2475
95
3.96
9283
4.
3301
27
5.50
2.67
9266
2.
9769
62
3.17
5426
3.
2746
59
3.38
8140
3.
5723
55
4.36
621
1 4.
7631
40
6.00
2.92
2836
3.
2475
95
3.46
4102
3.
5723
55
3.69
6152
3.
8971
14
4.76
3140
5.
1961
52
8.00
3.89
7114
4.
3301
27
4.61
8802
4.
7631
40
4.92
8203
5.
1961
52
6.35
0853
6.
9282
03
0.21
6506
0.
2706
33
0.32
4760
0.
3788
86
0.43
3013
0.
4871
39
0.54
1266
0.
6495
19
0.75
7772
0.
8118
99
0.86
6025
1.
0825
32
1.35
3165
1.
6237
98
1.89
4431
2.
1650
64
2.70
6329
3.
2475
95
3.78
8861
4.
3301
27
4.87
1393
5.
4126
59
5.95
3925
6.
4951
91
8.66
0254
0.23
8157
0.
2976
96
0.35
7235
0.
4167
75
0.47
6314
0.
5358
53
0.59
5392
0.
7144
71
0.83
3549
0.
8930
89
’ 0.
9526
28
1.19
0785
1.
4884
8 1
1.78
6177
2.
0838
74
2.38
1570
2.
9769
62
3.57
2355
4.
1677
47
4.76
3140
5.
3585
32
5.95
3925
6.
5493
17
7.14
4710
9.
5262
79
L
TABL
E 3
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AMERICAN NATIONAL STANDARDS FOR SCREW THREADS
(Published by The American Society of Mechanical Engineers)
................................. TITLE OF STANDARD
Unified Inch Screw Threads (UN and UNR Thread Form) B1.1-1989
Screw Thread Gaging Systems for Dimensional Gages and Gaging for Unified Inch Screw Threads ................................ B1.2-1983(R1991)
Acceptability - Inch and Metric Screw Threads (UN. UNR. UNJ. M. and MJ) . . . . . . . . . . . B1.3M-1986 Acme Screw Threads ................................................................. B1.5-1988 Nomenclature. Definitions. and Letter Symbols for Screw Threads . . . . . . . . . . . . . . . Bl.7M-l984(R1992) Stub Acme Screw Threads ............................................................ 81.8-1988
Thread Engagement .......................................................... B1.9-1973(R1992) Unified Miniature Screw Threads ............................................... 81.10-1958(R1988)
Buttress Inch Screw Threads 7"/45" Form With 0.6 Pitch Basic Height of
..................................................
a ...............................................
Microscope Objective Thread 51.1 1-1958(R1989) Class 5 Interference-Fit Thread B1.12M-l987(R1992) Metric Screw Threads - M Profile B1.13M-l983(R1989)
Metric Screw Threads for Commercial Mechanical
Gages for Metric Screw Threads for Commercial Mechanical
........................................... Gages and Gaging for Metric M Screw Threads ................................ Bl.16M-l984(R1992)
Fasteners - Boundary Profile Defined ...................................... Bl.18M-l982(R1987)
Fasteners - Boundary Profile Defined ...................................... BI.19M-l984(R1992) Pipe Threads. General Purpose (Inch) ......................................... B1.20.1-1983(R1992) Dryseal Pipe Threads (Inch) .................................................. B1.20.3-1976(R1982) Dryseal Pipe Threads (Metric Translation of B1.20.3-1976) ...................... B1.20.4-1976(R1982) Gaging for Dryseal Pipe Threads (Inch) .............................................. B1.20.5-1991
of B1.20.5-1978) ............................................................... B1.20.6M-1984
Gages and Gaging for MJ Series Metric Screw Threads ............................... B1.22M-1985
and Rounding Dimensions ........................................................ B1.30M-1992
Gaging for Dryseal Pipe Threads (Metric Translation
Hose Coupling Screw Threads (Inch) B1.20.7-1991 Metric Screw Threads - MJ Profile B1.21M-1978
Screw Threads - Standard Practice for Calculating
................................................ .................................................
The ASME Publications Catalog shows a complete list of all the Standards published by the Society . For a complimentary catalog. or the latest information about our publications. call 7-800-THE-ASME ( 1.800.843.2763) .
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Copyright ASME International Provided by IHS under license with ASME
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Copyright ASME International Provided by IHS under license with ASME
Not for ResaleNo reproduction or networking permitted without license from IHS
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