GB/T 14791-2013Screw threads -- Vocabulary (English PDF)

Foreword

This standard GB/T 1.1-2009 given rule drafting.

This standard replaces GB/T 14791-1993 "threaded term." This standard compared with GB/T 14791-1993, the main technical change Into.

--- The standard adds 25 new terms. helix lead (3.1.2), spiral lead angle (3.1.3), symmetrical thread (3.2.4), asymmetrically Thread (3.2.5), the guide thread (3.2.13), the adjacent flank (4.9.1), the same name as the flank (4.9.2), the tooth (4.10), alveolar (4.11), Alveolar pitch (6.2), the cumulative pitch (6.3), the number of teeth (6.4), alveolar lead (6.6), thread contact height (7.2), fitted long thread Degree (7.4), alveolar pitch deviation (8.1.2), alveolar lead deviation (8.1.5), the maximum material difference (8.2.1), tolerance code (8.2.2), reference plane (10.9), to accommodate the length of (10.10), the diameter of the conical taper (10.11), in close distance (10.12), thread tension Intensity area (11.1), the shear strength of the threaded area (11.2).

--- "Original triangle" "Basic tooth type" relationship with. the 1993 edition of the "original triangle" Export "Basic tooth type" (1993 edition 3.1.2 and 3.1.4); this standard from "Basic tooth type" Export "original triangle" (see 4.1 and 4.5).

--- "Flank" is defined. the 1993 version does not define the shape of the tooth side (the 1993 edition of 3.1.11); this standard is defined in parallel to the axis flank Rectilinear inner surface (see 4.9).

--- "Functional diameter" is defined 1993 Edition no clear position of the imaginary thread inclusive actual thread (1993 version 3.2.8); this standard Quasi clearly defined inclusive actual position of the imaginary thread in the thread "flank" Department (see 5.11).

--- "Pitch" is defined. the 1993 measure did not define a position on the pitch (1993 Version 3.3.1) flank; This standard defines spiro Pitch is the distance between the flank (see 6.1).

--- On the "flank contact height" and "thread contact height" Terminology.1993 Edition no clear distinction between the two terms, only a "connection Touch height "Terminology (1993 Version 4.1); This standard makes a distinction between the two terms, and gives a clear definition (see 7.1 and 7.2).

--- About "screwed length" and "thread assembly length" terms. the 1993 edition is no clear distinction between the two terms, only a "Length" terms (1993 edition 4.4); This standard makes a distinction between the two terms, and gives a clear definition (see 7.3 and 7.4).

--- The 1993 edition of "cumulative pitch error" and "lead the accumulated error" terms were changed to "the cumulative pitch deviation" and "cumulative Lead bias "term; and to redefine the definition (see 8.1.3 and 8.1.7).

--- Revised 1993 edition of "reference diameter" is defined (see 10.4).

--- Use the "pull tight balance" term instead of the 1993 edition of "tightening margin" terms; and delete the definitions of the terms in the 1993 edition of the "minimum Two entities within the limits thread "and" taper thread "(see 10.8).

This standard uses the translation method identical with ISO 5408:2009 "Thread the term" (in English).

Consistency correspondence with international standards in this standard references of our standards are as follows.

Part 1 (GPS) Limits and fits GB/T 1800.1-2009 Geometrical product specifications. tolerances, deviations and fits the base Base (ISO 286-1. 1988, MOD) this standard makes the following editorial changes.

--- Increased the Chinese Pinyin index terms.

--- Modify the title of Appendix B and Table B.1 in the order of content; deleted chapter numbers are listed in the table.

--- Deleted the Chapter 1 (range) on the ISO standard official languages.

--- "Single diameter" is defined. ISO 5408:2009 thread limit measure the axial length within the term defined as an alveolar width, the most commonly recommended amount behind its definition of the needle (ball volume) measurements contradict; this standard deleted the measure defined within ISO Limit the amount of content length (see 5.10).

Thread term

1 Scope

This standard specifies the basic terms and their definitions thread.

This standard applies to symmetric and asymmetric screw threaded, or threaded cylindrical and tapered threads.

When there is more than one corresponds to a defined term, preference should be given black bold terms.

Appendix A lists some of the standard text does not give the definition of the term.

With Chinese and English terminology thread equivalent French, German, Japanese and Swedish terminology, see Appendix B.

2 Normative references

The following documents for the application of this document is essential. For dated references, only the dated version suitable for use herein Member. For undated references, the latest edition (including any amendments) applies to this document.

ISO 286-1. Section 11988 of the ISO system of limits and fits. tolerances, deviations and infrastructure (ISO systemof fit limitsandfits-Part 1. Basesoftolerances, deviationsandfits)

3 General terms

13 Diameter

Trail minordiameter

With external thread (3.2.6) tooth bottom (4.13) or internal thread (3.2.7) crest (4.12) tangent to imaginary cylindrical or conical diameter.

Figure 10, Figure 11 and Figure 13.

Note 1. The conical thread (3.2.3), (5.12) path at a location different from the thread axis is different.

Note 2. When the minor diameter external thread (3.2.6) tooth design type (4.6) on a path different from the basic tooth type (4.5) on, the design trail use on behalf of the tooth type no. d3.

BPD crestdiameter

Crest (4.12) tangent to imaginary cylindrical or conical diameter of the thread (3.2.1).

See Figures 11 and 13.

NOTE. It is the external thread (3.2.6) of large diameter (5.2) or internal thread (3.2.7) trails (5.3).

Bottom diameter rootdiameter d1 d3 D4 (metric thread) Bottom teeth (4.13) tangent to imaginary cylindrical or conical diameter of the thread (3.2.1).

See Figures 11 and 13.

Note 1. It is the external thread (3.2.6) trails (5.3) or internal thread (3.2.7) of large diameter (5.2).

Note 2. When the large-diameter internal thread (3.2.7) tooth design type (4.6) on (5.2) is different from the size of the large diameter of its basic tooth type (4.5) on the large diameter tooth type design on the make with code D4.

Note 3. When the small-diameter external thread (3.2.6) tooth design type (4.6) on (5.3) is different from the size of its small-diameter basic tooth type (4.5) on the trail on the type of tooth design makes with code d3.

Diameter cylindrical pitchcylinder an imaginary cylinder, the cylinder bus tooth thickness (6.8) by means of threaded barrel (3.2.2) and alveolar width (6.9) equal place.

Diameter cone pitchcone an imaginary cone, the cone. (3.2.3) on the tooth thickness (6.8) by a threaded cone and alveolar width (6.9) equal place.

Diameter line pitchline Diameter cylinder (5.6) in diameter or cone (5.7) bus.

Figures 10 and 13.

Diameter pitchdiameter D2 d2 6.2 Alveolar pitch two-flankpitch P2 Two adjacent alveolar (4.11) corresponds to the line of symmetry of the axial distance between two points in the radial line (5.8) on. The optimum amount usually used needle or the amount of ball Measurements.

Figure 16.

Note. Pitch is only available for symmetric alveolar thread (3.2.4), the alveolar (4.11) line of symmetry perpendicular to the axis of the thread (5.12).

Cumulative pitch Psum Apart two or more pitch (6.1) two tooth (4.10) and the pitch between each.

The number of teeth threadsperinch (tpi) Thread (3.1) pitch (6.1) the number of the axial length of each contained 25.4mm.

NOTE. This term is mainly used for inch screw threads. The number of teeth is the reciprocal value of the inch pitch.

Lead lead

Ph (metric thread)

L (inch screw threads) Closest two namesake flank (4.9.2) with a diameter line (5.8) intersect the axial distance between two points.

See Figure 17.

NOTE. Lead is a point along the corresponding axial displacement of helix rotation on (3.1.1) in diameter column (5.6) in diameter or cone (5.7).

17 Lead and lead alveolar

Alveolar lead two-flanklead Ph2 Two nearest neighbor in the same line of symmetry alveolar (4.11) in the corresponding axial distance between two points in the radial line (5.8) on. usually the optimum amount of needle use or amount of the ball is measured.

See Figure 17.

NOTE. alveolar lead only applies to symmetrical threads (3.2.4), the alveolar (4.11) line of symmetry perpendicular to the axis of the thread (5.12).

Lead angle Lead angle phi (metric thread) lambda (inch screw threads) in diameter column (5.6) in diameter or cone (5.7) in the thread axis angle between the plane of the spiral (3.1.1) with the vertical tangent (5.12).

Note 1. For metric thread, which is calculated as tanphi = Ph pid2 ; For inch system thread, which is calculated as tanlambda = pid2

Note 2. conical thread (3.2.3), their different thread axis (5.12) L angular position is different.

Teeth thick ridgethickness A tooth (4.10) adjacent flank (4.9.1) with a diameter line (5.8) intersect the axial distance between two points.

Alveolar wide groovewidth A alveolar (4.11) adjacent flank (4.9.1) with a diameter line (5.8) intersect the axial distance between two points.

7 threaded engagement with related terms 7.1 Flank contact height flankoverlap; depthofthreadengagement H1 in two coaxial mating threads (3.2.1) tooth type (4.4) on its flank (4.9) coincides with the radial height portion.

See Figures 11 and 18.

Explanation.

1 --- internal thread;

2 --- external thread.

18 Thread contact height and flank contact height

Thread contact height threadoverlap H0 in two coaxial mating threads (3.2.1) tooth type (4.4), the external thread (3.2.6) crest (4.12) to the inner diameter of the thread crest between (3.2.7) the distance, that is within the outer thread (3.2.6; 3.2.7) of the tooth-type overlapping radial height.

See Figures 11 and 18.

Screwed length lengthofthreadengagement lE (10.3) contact with each other axial length of the two mating thread (3.2.1) Effective thread.

Figure 15 and 19.

Explanation.

1 --- internal thread;

2 --- external thread.

Figure 19 is screwed assembly length and thread length

Threaded mounting length lengthofassembly lA (3.2.1) screwed the axial length of the two mating threads.

Figure 19.

Note. threaded mounting length allowed to contain lead thread (3.2.13) chamfering and (or) threaded closure (3.2.12).

Large diameter gap majorclearance ac1 in the design tooth type (4.6), the radially inner threaded coaxial assembly (3.2.7) tooth bottom (4.13) and the external thread (3.2.6) crest (4.12) between the distance.

Figure 11.

Trail gap minorclearance ac2 in the design tooth type (4.6), the radially inner threaded coaxial assembly (3.2.7) crest (4.12) and the external thread (3.2.6) tooth bottom (4.13) between the distance.

Figure 11.

Travel kinematictravel; kinematicpath Two mating thread (3.2.1) the relative axial displacement relative rotational angle of a generated. This term is often used for transmission thread.

See Figure 20.

a trip.

b angle of rotation.

Figure 20 stroke

8 with the threaded tolerance test and related terms 8.1 pitch, lead, flank angle and its diameter equivalent 8.1.1 Pitch deviation deltaP Pitch (6.1) of the actual value of the difference between its basic values.

8.1.2

Alveolar pitch deviation two-flankpitchdeviation deltaP2 Alveolar pitch (6.2) of the actual value of the difference between its basic values.

8.1.3

Cumulative pitch deviation deltaPsum Within the specified thread (3.2.1) the length of the actual cumulative tooth pitch of any two (4.10) between (6.3) the value of their underlying value of the accumulated pitch the biggest difference between the absolute value of the deviation.

See Figure 21.

NOTE. In some cases, the length of the thread of this provision may be screwed length (7.3). For pipe thread, length of this provision may be 25.4mm.

21 Cumulative pitch deviation

8.1.4

Lead deviation deltaPh (metric thread) deltaL (inch screw threads) Lead (6.5) of the actual value of the difference between its basic values.

8.1.5

Alveolar lead deviations two-flankleaddeviation deltaPh2 Alveolar lead (6.6) of the actual value of the difference between its basic values.

8.1.6

Stroke deviation kinematictraveldeviation the basic difference between the actual value of its stroke (7.7) in.

8.1.7

Cumulative lead deviation deltaPhsum Within a specified thread length, the same spiral face any two flank (4.9) and the radial line (5.8) intersects the actual axial distance between two points the basic difference between the value of its maximum absolute value of the deviation.

See Figure 22.

NOTE. In some cases, the length of the thread of this provision may be screwed length (7.3). For pipe thread, length of this provision may be 25.4mm.

22 Cumulative lead error

8.1.8

Flank angle deviation deltabeta (metric thread) Flank angle (4.17) of the actual value of the difference between its basic values.

8.1.9

Diameter equivalent pitchdiameterequivalent by a pitch deviation (8.1.1) or lead deviation (8.1.4) and (or) flank angle deviation (8.1.8) the functional diameter (5.11) of the amount caused by the change.

Measurements typically utilize thread gauge indicating the differential test.

Note 1. External thread (3.2.6), wherein the equivalent diameter is positive; internal thread (3.2.7), wherein the equivalent diameter is negative.

Note 2. The "equivalent diameter" can also be broken down into "pitch deviation equivalent diameter" and "flank angle deviation in equivalent diameter." 8.2 inch screw threads 8.2.1 the maximum difference alowance entity Internal thread (3.2.7) of the maximum diameter of the outer thread entity (3.2.6) corresponding to the difference between the maximum diameter of the entity.

Note 1. For a clearance fit inch screw threads, the largest entity equal to the absolute value of the difference between the basic bias.

Note 2. For a clearance fit inch screw threads, the biggest difference is the entity with the minimum gap between the threads (positive); for interference fit inch screw threads, the largest entity difference is the maximum amount of thread interference fit between the (negative).

8.2.2

Tolerance code classofthread Tolerance of numbers and letters that is marked by the code, indicating the location of standard tolerance grades and thread.

9 and asymmetrical thread related terms 9.1 Bearing flank loadflank Deputy in the external thread withstand axial load flank (4.9).

Non-bearing flank clearanceflank Deputy thread is not subjected to an external axial load flank (4.9).

Guide flank leadingflank when the thread is about to assemble, with the face of its thread flank of the workpiece (4.9).

Follow flank folowingflank when the thread is about to assemble, with his back to its flank threaded workpiece (4.9).

10 and the seal pipe thread related terms 10.1 Complete thread Crest (4.12) and bottom teeth (4.13) has a threaded complete shape (3.2.1).

See Figure 23.

NOTE. When the guide thread (3.2.13) of the axial length of the chamfer pitch no more than one (6.1), this is included in the complete guide screw thread length.

10.2

Incomplete thread Bottom teeth (4.13) form a complete crest (4.12) due to the intersection of the cylindrical surface of the workpiece shape of incomplete thread (3.2.1).

See Figure 23.

10.3

Effective thread usefulthread; effectivethread the complete thread (10.1) and incomplete thread (10.2) composed of threads (3.2.1). It does not contain pintail (3.2.12).

See Figure 23.

10.6

Reference distance gaugelength Substrate distance the axial distance from the reference plane (10.5) into the conical external threads (3.2.3,3.2.6) small end face.

See Figure 23.

10.7

Assembly margin fittingalowance in the conical outer thread (3.2.3,3.2.6) effective thread reference plane (10.5) after (10.3) length. It provides a minimum physical shape in the state assembly of that thread (3.2.7) in.

See Figure 23.

10.8

Wrenching margin wrenchingalowance Hands screwed wrench required for effective thread (10.3) length. When wrenching, it accommodates relative motion between two mating threads of the workpiece.

See Figure 23.

10.9

Reference plane when the test thread (3.2.1), the workpiece thread gauge reading test values \u200b\u200b(position deviation reference plane) referenced visible end face.

See Figure 23.

NOTE. It is an internal thread (3.2.7) or large end externally threaded workpiece (3.2.6) of small parts of the end face.

10.10

Accommodate the length accommodationlength from the large end internal thread (3.2.7) to interfere with an external thread (3.2.6) pull the axial distance between the first obstacle encountered screwed tight between.

10.11

Diameter conical taper taperofpitchcone Taper taperofthread in diamet...