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ASME B1.13M-2005 pdf download

ASME B1.13M-2005 pdf download.Metric Screw Threads: M Profile.
1 GENERAL 1.1 Scope This Standard contains general metric standards for a 60 deg symmetrical screw thread with a basic ISO 68-1 profile designated M profile. The M profile threads of tolerance class 6H/6g are intended for metric applica- tions where inch class 2A/2B have been used. At the minimum material limits, the 6H/6g results in a looser fit than the 2A/2B. Tabular data is also provided for a tighter tolerance fit external thread of class 4g6g, which is approximately equivalent to the inch class 3A but with an allowance applied. Formulation and tolerancing data is included for applications requiring other fits. NOTE: A 4H5H/4h6h is approximately equivalent to a class 3A/3B fit in the inch system. 1.2 Interchangeability Threads produced to this Standard are fully inter- changeable with threads conforming to other National Standards that are based on ISO 68-1 basic profile and ISO 965-1 tolerance practices. 1.2.1 Assembly. Threads produced in accordance with M profile and MJ profile (ASME B1.21M) design data will assemble with each other. However, external MJ threads will encounter interference on the root radii with internal M thread crests when both threads are at maximum material condition. 1.3 References The latest issues of the following documents form a part of this Standard to the extent specified herein. ASME B1.3, Screw Thread Gaging Systems for Dimensional Acceptability — Inch and Metric Screw Threads (UN, UNR, UNJ, M, and MJ) ASME B1.7M, Nomenclature, Definitions, and Letter Symbols for Screw Threads ASME B1.16M, Gages and Gaging for Metric M Screw Threads ASME B1.21M, Metric Screw Threads: MJ Profile ASME B1.30, Screw Threads — Standard Practice for Calculating and Rounding Dimensions ASME B47.1, Gage Blanks ASME Y14.5, Dimensioning and Tolerancing Publisher: The American Society of Mechanical Engi- neers (ASME), Three Park Avenue, New York, NY 10016-5990; Order Department: 22 Law Drive, Box 2900, Fairfield, NJ 07007-2900 1 ASTM F568M, Standard Specification for Carbon and Alloy Steel Externally Threaded Metric Fasteners Publisher: The American Society for Testing and Materi- als (ASTM), 100 Barr Harbor Drive, West Consho- hocken, PA 19428-2959 ISO 3, Preferred Numbers — Series of Preferred Numbers ISO 68-1, ISO General Purpose Screw Threads — Basic Profile — Part 1: Metric Screw Threads ISO 261, ISO General Purpose Metric Screw Threads — General Plan ISO 724, ISO Metric Screw Threads — Basic Dimensions ISO 898-1, Mechanical Properties of Fasteners — Part 1: Bolts, Screws, and Studs ISO 965-1, ISOGeneral Purpose Metric Screw Threads — Tolerances — Part 1: Principles and Basic Data Publisher: International Organization for Standardiza- tion (ISO), 1 rue de Varembe´ , Case Postale 56, CH-1211, Gene`ve 20, Switzerland/Suisse SAE J1199, Mechanical and Material Requirements for Metric Externally Threaded Steel Fasteners Publisher: Society of Automotive Engineers (SAE), 400 Commonwealth Drive, Warrendale, PA 15096-0001 1.4 Acceptability Acceptability of product threads shall be in accor- dance with ASME B1.3. Gages and gaging are in accor- dance with ASME B1.16M. 1.5 Reference Temperature The reference temperature is 20°C for dimensions defined by this system. 1.6 General Symbols The general symbols used to describe the metric screw thread forms are shown in Table 1. 1.7 Units All dimensions and all values in the formulas are expressed in millimeters unless otherwise noted. Values intermsofsharp vee-thread height(heightoffundamen- tal triangle), H, are used to be consistent with ISO Stan- dards, but actual formulations and calculations are based on values of pitch, P. See Table 2.
2 TERMINOLOGY 2.1 Definitions allowance: the prescribed difference between the design (maximum material) size and the basic size. It is numeri- cally equal to the absolute value of the ISO term funda- mental deviation. NOTE: Allowance is not an ISO metric screw thread term but will be used together with the ISO term fundamental deviation. basic thread profile: the cyclic outline, in an axial plane, of the permanently established boundary between the provinces ofthe external and internal threads. All devia- tions are with respect to this boundary. See Figs. 1 and 4. bolt thread (external thread): the term used in ISO metric thread standards to describe all external threads. All symbols associated with external threads are designated with lowercase letters. This Standard will refer only to external threads in accordance with U.S. practice. 2 crest diameter: the major diameter of an external thread and the minor diameter of an internal thread. design profiles: the maximum material profiles permitted for external and internal threads for a specified tolerance class. See Figs. 2 and 3. deviation: in ISO usage, the algebraic difference between a size (actual, maximum, minimum, etc.) and the corres- ponding basic size. The term deviation does not necessar- ily indicate an error. fit: the general term used to signify range of tightness or looseness that results from application of a specific combination of allowances and tolerances in mating parts. fundamental deviation: for standard threads, the deviation (upper or lower) closer to the basic size. It is the upper deviation, es, for an external thread and the lower devia- tion, EI, for an internal thread. See Fig. 4; also see allow- ance and tolerance position.

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