1、AN AMERICAN NATIONAL STANDARD ASME Y14.2-2014(Revision of ASME Y14.2-2008)Line Conventions and LetteringEngineering Drawing and Related Documentation PracticesASME Y14.2ADOPTION NOTICEASME Y14.2, Line Conventions and Lettering, was adopted on 30 September 2008 for use by the Department ofDefense(DoD
2、).ProposedchangesbyDoDactivitiesmustbesubmittedtotheDoDAdoptingActivity:Commander,U.S. Army Research, Development and Engineering Center (ARDEC), ATTN: RDAR-EIQ-SE, Picatinny Arsenal,NJ 07806-5000. Copies of this document may be purchased from The American Society of Mechanical Engineers(ASME), Two
3、Park Avenue, New York, NY 10016-5990; http:/www.asme.org.Custodians: Adopting Activity:Army AR Army ARNavy SAAir Force 16 (Project DRPR-2008-006)Review Activities:Army CR, IE, MI, PT, TM2Navy AS, CG, CH, EC, MC, NP, TDAir Force 13, 99DLADHOSDSENSANSOther CM, MP, DC2NOTE: The activities listed above
4、were interested in this document as of the dateof this document. Since organizations and responsibilities can change, youshould verify the currency of the information above using the ASSIST Onlinedatabase at https:/assist.dla.mil.ASMC N/A AREA DRPRDISTRIBUTION STATEMENT A. Approved for public releas
5、e; distribution is unlimited.ASME Y14.2-2014Revision of ASME Y14.2-2008Line Conventionsand LetteringEngineering Drawing and RelatedDocumentation PracticesAN AMERICAN NATIONAL STANDARDTwo Park Avenue New York, NY 10016 USADate of Issuance: January 30, 2015This Standard will be revised when the Societ
6、y approves the issuance of a new edition.Periodically certain actions of the ASME Y14 Committee may be published as Cases. Cases arepublished on the ASME Web site under the Y14 Committee Page at go.asme.org/Y14committee asthey are issued.Errata to codes and standards may be posted on the ASME Web si
7、te under the Committee Pages toprovide corrections to incorrectly published items, or to correct typographical or grammatical errorsin codes and standards. Such errata shall be used on the date posted.The Y14 Committee Page can be found at go.asme.org/Y14committee. There is an option availableto aut
8、omatically receive an e-mail notification when errata are posted to a particular code or standard.This option can be found on the appropriate Committee Page after selecting “Errata” in the “PublicationInformation” section.ASME is the registered trademark of The American Society of Mechanical Enginee
9、rs.This code or standard was developed under procedures accredited as meeting the criteria for American NationalStandards. The Standards Committee that approved the code or standard was balanced to assure that individuals fromcompetent and concerned interests have had an opportunity to participate.
10、The proposed code or standard was madeavailable for public review and comment that 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 act
11、ivity.ASME does not take any position with respect to the validity of any patent rights asserted in connection with anyitems mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability forinfringement of any applicable letters patent, nor assumes any su
12、ch liability. Users of a code or standard are expresslyadvised that determination of the validity of any such patent rights, and the risk of infringement of such rights, isentirely their own responsibility.Participation by federal agency representative(s) or person(s) affiliated with industry is not
13、 to be interpreted asgovernment or industry endorsement of this code or standard.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.The American Society of Mechanical EngineersTwo Park Avenue, Ne
14、w York, NY 10016-5990Copyright 2015 byTHE AMERICAN SOCIETY OF MECHANICAL ENGINEERSAll rights reservedPrinted in U.S.A.CONTENTSForeword ivCommittee Roster . vCorrespondence With the Y14 Committee vi1 General. 12 References 23 Definitions 24 Line Conventions 35 Arrowheads. 56 Lettering 5Figures3-1 Lin
15、e Widths and Types 74-1 Applications of Lines 84-2 Hidden Line Techniques and Symmetry Line Application . 94-3 Section Lining of Adjacent Parts 94-4 Direction of Section Lines 104-5 Full Section 104-6 Outline Section Lining . 104-7 Arrowhead Placement on Dimension Lines . 114-8 Special Applications
16、of Extension Lines 114-9 Termination of Leaders 124-10 Phantom Line Applications 135-1 Arrowhead Styles 146-1 Inclined Letters 146-2 Vertical Letters 15Table6-1 Minimum Letter Height Proportions . 15iiiFOREWORDThisStandardisa revisionofASMEY14.2-2008,LineConventions andLettering.Thesuccessfulrevisio
17、n of this Standard is attributed to the Subcommittee members and their respective compa-nies who participated in the review process.The more substantial changes are as follows:(a) Due to the addition of the Y14 Policy 3 statements, all the paragraphs and figures wererenumbered.(b) Examples for leade
18、rs for datum targets were added to Fig. 4-9.(c) A datum target line was added as an example of a phantom line.(d) The width of a dimensional arrow is constrained to the width of the dimension line.(e) Letter height has changed from specific heights to proportions of the letter height.Suggestionsfori
19、mprovementofthisStandardarewelcome,andshouldbesenttoTheAmericanSociety of Mechanical Engineers; Attention: Secretary, Y14 Standards Committee;Two Park Avenue, New York, NY 10016-5990.This Standard was approved as an American National Standard on December 8, 2014.ivASME Y14 COMMITTEEEngineering Drawi
20、ng and Related Documentation Practices(The following is the roster of the Committee at the time of approval of this Standard.)STANDARDS COMMITTEE OFFICERSW. A. Kaba, ChairJ. I. Miles, Sr., Vice ChairF. Constantino, SecretarySTANDARDS COMMITTEE PERSONNELA. R. Anderson, Dimensional Dynamics, LLCF. Bak
21、os, Jr., ConsultantJ. V. Burleigh, UnaffiliatedF. Constantino, The American Society of Mechanical EngineersD. E. Day, TEC-EASE, Inc.K. Dobert, Siemens PLM SoftwareB. A. Harding, Purdue UniversityD. H. Honsinger, ConsultantR. C. Jensen, Hexagon Metrology, Inc.W. A. Kaba, Spirit AeroSystems, Inc.SUBCO
22、MMITTEE 2 LINE CONVENTIONS AND LETTERINGP. J. McCuistion, Chair, MultimacJ. V. Burleigh, UnaffiliatedR. G. Campbell, Harper CollegeR. R. Cruz, GE AviationvA. Krulikowski, Effective Training, Inc.E. F. McCarthy, Raytheon Missile SystemsP. J. McCuistion, MultimacJ. D. Meadows, James D. Meadows Order D
23、epartment: 22 Law Drive, P.O. Box 2900, Fairfield, NJ 07007-2900 (www.asme.org)3 DEFINITIONSFor definitions and illustrations of line types, see Fig. 3-1.2ASME Y14.2-20144 LINE CONVENTIONSLine conventions describe the size, construction, and application of the various lines used in making drawings.P
24、aragraphs 4.1 through 4.14 identify the type and style of lines for use on drawings.4.1 Line WidthsTwo widths of lines should be used on drawings (see Fig. 3-1). The ratio of line widths should be two-to-one(2:1). Recommended line widths are 0.3 mm minimum for thin lines and 0.6 mm minimum for thick
25、 lines. All linesof the same type shall be uniform throughout the drawing.4.2 Line SpacingSpacing between parallel lines may be exaggerated to a maximum of 3 mm, so there is no fill-in when the drawingis reproduced.4.3 Visible LinesVisible lines are continuous and shall be used for representing visi
26、ble edges or contours of objects (see Figs. 3-1and 4-1).4.4 Projection LinesWhenused,projectionlinesindicatethelineofsightbetweentwosuccessiveorthographicviews.SeeASMEY14.3.4.5 Hidden LinesWhen used, hidden lines represent hidden edges and contours. They consist of short evenly spaced dashes andare
27、used to show the hidden features of an object. See Figs. 3-1 and 4-1. The length of the dashes may vary slightlyin relation to the scale of the view.Hidden lines should begin and end with a dash in contact with the visible or hidden line from which they startor end, except when such a dash would for
28、m a continuation of a visible line or when a CAD system has limitationsthat cannot comply with these requirements. Dashes should join at corners, and arcs should start with dashes attangent points. See Fig. 4-2.When features located behind transparent materials are depicted, they shall be treated as
29、 concealed features andshown with hidden lines. Hidden lines should be omitted when their use is not required for the clarity of thedrawing.4.6 Section LinesWhen used, section lines show surfaces cut by a cutting plane. They are drawn as a pattern of straight, equallyspaced, parallel lines used to i
30、ndicate the cut surfaces of an object in section views. See Figs. 3-1 and 4-1.4.6.1 General Principles. Cut surfaces of sectional views may be identified by using section lines. Section linesare optional and may be used when necessary to distinguish individual components of an assembly or to disting
31、uishdifferent surface levels of a full or partial section through a part. See ASME Y14.3.Lettering should not be placed in section areas. However when it is unavoidable, the section lines shall be omittedin the area for the lettering. When several adjacent parts are shown in a section view, the part
32、s may be sectionedas shown in Fig. 4-3. For section views of thin materials, see ASME Y14.3.4.6.2 Direction and Spacing. Section lines should be drawn at a 45-deg angle within the view. See Fig. 4-3,illustration(a). Onadjacentparts,the sectionlinesshould bedrawninthe oppositedirection.SeeFig. 4-3,il
33、lustration(b). For additional adjacent parts, any suitable angle may be used to make each part stand out separately andclearly. See Fig. 4-3, illustration (c). A suitable angle should be chosen to avoid section lines that are parallel orperpendicular to visible lines. See Fig. 4-4. Section lines sha
34、ll not meet at common boundaries.Section lines shall be uniformly spaced a minimum of 1.5 mm, and spaced as generously as possible and yetpreserve the unity and contrast of the sectioned areas. See Fig. 4-5.Outline section lines are drawn adjacent to the boundaries only of the sectioned area, and ma
35、y be used for largeareas when section lines are required, provided clarity is not sacrificed. See Fig. 4-6.4.7 Center LinesWhen used, center lines represent axes, center points, or center planes of symmetrical parts and features, boltcircles, and paths of motion. See Figs. 4-1 and 4-2.3ASME Y14.2-20
36、14Center lines shall start and end with long lines and shall intersect by crossing the long lines or short dashes. SeeFig. 3-1. The long line portion of the center line may vary in length depending on the scale of the view. Centerlines shall extend uniformly and distinctly a short distance beyond th
37、e object or feature. The center line may beextended for dimensioning or for some other purpose.Center lines shall not extend through the space between views. Short center lines may be unbroken when noconfusion results with other lines.4.8 Symmetry LinesSymmetry lines are used to identify a plane of
38、symmetry. The plane of symmetry is identified by placing twoshort parallel lines (symmetry lines), drawn at right angles, crossing a center line near each end and outside theboundary of the part. See Fig. 3-1.Symmetry lines are used when representing partially drawn views and partial sections of sym
39、metrical parts. SeeFig. 4-2. Visible and hidden lines in symmetrical views may extend past the center line when clarity is improved.4.9 Dimension, Extension, and Leader LinesThese are solid lines used to dimension drawings as described in paras. 4.9.1 through 4.9.3.2. See ASME Y14.5.4.9.1 Dimension
40、Lines. Dimension lines are used to indicate the extent and direction of dimensions, and areterminated with uniform arrowheads. See Figs. 3-1 and 4-1. Arrowheads shall be drawn within the limits of theextension lines when possible. See Fig. 4-7, illustration (a). When inadequate space is available, t
41、he dimension linesand arrowheads may be shown outside the extension lines. See Fig. 4-7, illustration (b).4.9.2 Extension Lines. Extension lines are used to indicate(a) the point or line on the drawing to which the dimension applies. See Figs. 3-1 and 4-1.(b) the extension of a surface to a theoreti
42、cal intersection. See Fig. 4-8.4.9.3 Leader Lines. When used, leader lines direct notes, dimensions, symbols, item numbers, or part numberson the drawing. See Figs. 3-1 and 4-1. A leader line should be a straight inclined line, except for a short horizontalportion extending to the center of the heig
43、ht of the first or last letter or character of the note. Leader lines mayconsist of one or more line segments see Fig. 4-9, illustrations (d), (e), and (f) or two line segments see Fig. 4-9,illustrations (a), (b), and (c). Leaders may be drawn with a hidden line style when pointing to a hidden surfa
44、ce.The horizontal portion of the leader shall not underline the note, and may be omitted entirely.A vertical line may be used at the end of the leader to group information. When the vertical line is used, theleader line may terminate at any point on the vertical line.4.9.3.1 Terminate leaders as fol
45、lows:(a) without a terminator, when they end on a dimension line. See Fig. 4-9, illustration (a).(b) with a dot 1.5 mm minimum diameter, when they end within outlines of an object. See Fig. 4-9, illustration (b).(c) with an arrowhead, when they end on the outline of an object. See Fig. 4-9, illustra
46、tion (c).(d) without a terminator for a datum target. See Fig. 4-9, illustrations (d), (e), and (f).4.9.3.2 Leader lines(a) should not cross(b) should not be excessively long(c) shall not be parallel to adjacent dimension, extension, or section lines(d) shall not be drawn at small angles to terminat
47、ing surfaces(e) shall not be vertical or horizontal4.10 Cutting-Plane and Viewing-Plane LinesWhen used, cutting-plane and viewing-plane lines indicate the location of cutting planes for sectional views andthe viewing position for removed views. See Figs. 3-1 and 4-1. Cutting-plane and viewing-plane
48、lines shall bedrawn to stand out clearly on the drawing. The ends of the lines are at 90 deg, and terminated by arrowheads toindicate the direction of sight for viewing. See Fig. 4-1 and ASME Y14.3. Three forms of cutting-plane andviewing-plane lines are as follows:(a) evenly spaced dashes. See Fig.
49、 3-1 (line 9).(b) alternating long dashes and pairs of short dashes. The long dashes may vary in length, depending on thesize of the drawing. See Fig. 3-1 (line 10).(c) Figure 3-1 (line 11), same as lines 9 and 10, except the dashes between line ends are omitted.4ASME Y14.2-20144.11 Break LinesBreak lines are used when complete views are not required. The two forms of break lines are(a) freehand line. See Fig. 3-1 (line 12) and Fig. 4-9.(b) long lines joined by zigzags. See Fig. 3-1 (line 13) and Fig. 4-10, illustration (a).4.12 Phantom LinesWhen used, phanto
