公制锥外螺纹及配合的平行内螺纹 第1部分：尺寸、公差和检验

Metric taper external and mating parallel internal screw threads

Part 1: Dimensions, tolerances and inspection

ICS 21.040.10

Supersedes DIN 158, August 1986 edition.

Descriptors: Metric taper external screw threads, parallel internal screw threads, dimensions, tolerances, inspection.

Metrisches kegeliges Außengewinde mit zugehörigem zylindrischem Innengewinde – Teil 1: Nennmaße, Grenzabmaße, Grenzmäße und Prüfung

In keeping with current practice in standards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker.

Foreword

This standard has been prepared by the Section Gewinde of the Normenausschuß Technische Grundlagen (Fundamentals in Technology Standards Committee).

Amendments

The following amendments have been made to the August 1986 edition of DIN 158.

a) The number of the standard has been changed.

b) The values of thread height, h₃, have been amended (cf. table 2), taking into consideration the limit deviations specified in table 3.

c) The designation of taper external threads has been amended to include the letters 'keg' (taper) to distinguish them from parallel external threads.

d) The standard has been editorially revised.

Previous editions

DIN 158-1: 1954-06; DIN 158: 1971-04, 1986-08.

Dimensions in mm

1 Scope and field of application

This standard specifies profiles, dimensions and methods of verification for general purpose metric taper external threads intended to be mated with parallel internal threads with a basic profile as specified in ISO/DIS 68-1.

Taper external threads as specified in this standard are intended for self-sealing joints, such as those employed on pipe plugs, compression couplings and lubricating nipples. They can be used in all cases where a parallel threaded joint with washer is unsatisfactory for technical or economic reasons.

For fluids such as oils, other liquids and gases, no thread sealants are required for joints where the nominal size is small. For joints of greater nominal size, it is recommended that sealants be applied, since the leaktightness of such joints decreases as the diameter increases.

A short design taper external thread has been specified along with the standard design both to be mated with general purpose ISO metric parallel internal threads of tolerance class 4H for the pitch diameter and 5H for the minor diameter (as in ISO/DIS 965-1).

Continued on pages 2 to 10.

Translation by DIN-Sprachendienst.

In case of doubt, the German-language original should be consulted as the authoritative text.

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2 Normative references

This standard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the titles of the publications are listed below. For dated references, subsequent amendments to or revisions of any of these publications apply to this standard only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies.

DIN 13-1	ISO metric screw threads – 1 mm to 68 mm diameter coarse pitch threads – Nominal sizes*)
DIN 13-5	ISO metric screw threads – 1 mm and 1,25 mm fine pitch threads with diameters from 7,5 mm to 200 mm – Nominal sizes*)
DIN 13-6	ISO metric screw threads – 1,5 mm fine pitch threads with diameters from 12 mm to 300 mm – Nominal sizes*)
DIN 13-7	ISO metric screw threads – 2 mm fine pitch threads with diameters from 17 mm to 300 mm – Nominal sizes*)
DIN 13-19	ISO metric screw threads – Basic profile and manufacturing profiles*)
DIN 158-2	Metric taper external screw threads and mating internal parallel screw threads – Part 2: Gauges and gauging
DIN 2244	Screw threads – Terminology
ISO/DIS 68-1 : 1998	ISO general purpose screw threads – Basic profile
ISO/DIS 965-1 : 1998	ISO general purpose metric screw threads – Tolerances – Part 1: Principles and basic data
ISO/DIS 965-3 : 1998	ISO general purpose metric screw threads – Tolerances – Part 3: Deviations for constructional threads
ISO 1502 : 1996	ISO general-purpose metric screw threads – Gauges and gauging

3 Concepts amd symbols

3.1 Concepts

For the purposes of this standard, the concepts specified in DIN 2244 shall apply.

3.2 Symbols

For symbols, see table 1.

Table 1: Symbols

Symbol	Quantity
a	Distance from reference plane to external thread end
b	Gauge length
d	Major diameter of external thread at gauge plane
d2	Pitch diameter of external thread at gauge plane
d3	Minor diameter of external thread at gauge plane
D	Major diameter of internal thread
D1	Minor diameter of internal thread
D2	Pitch diameter of internal thread
d′	Major diameter of external thread at gauge plane
d′2	Pitch diameter of external thread at gauge plane
d′3	Minor diameter of external thread at gauge plane
H	Height of triangle of thread profile perpendicular to thread axis
H1	Flank overlapping
h3	Height of thread
l1	Useful length of external thread
l2	Useful length of internal thread
R	Root radius
P	Pitch
x	Thread run-out

*) At present at the stage of draft.

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4 Design profiles and designation

4.1 Taper external threads

The nominal sizes, limit deviations and limits of size are given in tables 2, 3 and 4, respectively.

d₂ = d − 0,649519 P

d₃ = d − 1,226869 P

H = (√3 / 2) P = 0,866025 P

H₁ = 0,541266 P = 5/8 H

h₃ = 0,613435 P

R = H/6 = 0,144338 P

Figure 1: Design profile of a metric taper external thread

Designation of a standard design M 30 × 2 keg external thread:

Thread DIN 158 – M 30 × 2 keg

Designation of a short design (short) M 30 × 2 keg external thread:

Thread DIN 158 – M 30 × 2 keg short

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Table 2: Nominal sizes for taper external threads

Thread size	Pitch, P	Useful thread length, l1		Maximum height of thread, h3		Dimension a		Thread dimensions at gauge plane		Gauge length b		Dimensions at gauge plane
		Standard design	Short design	Standard design	Short design	Standard design	Short design	Major diameter, d	Pitch diameter, d2	Minor diameter, d3	Standard design	Short design	d	d2	d3
M 5 keg	0,8	5	-	0,521	-	2	-	5	4,48	4,019	2,8	-	5,05	4,53	4,069
M 6 keg	1	5,5	4	0,659	0,644	2,5	2	6	5,35	4,773	3,5	3	6,063	5,413	4,836
M 8 × 1 keg								8	7,35	6,773			8,063	7,413	6,836
M 10 × 1 keg								10	9,35	8,773			10,063	9,413	8,836
M 12 × 1 keg								12	11,35	10,773			12,063	11,413	10,836
M 10 × 1,25 keg	1,25	7	6	0,823	0,807	3	2,2	10	9,188	8,466	5	4,2	10,125	9,313	8,591
M 12 × 1,25 keg								12	11,188	10,466			12,125	11,313	10,591
M 12 × 1,5 keg	1,5	8,5	7,5	0,983	0,967	3,5	2,5	12	11,026	10,16	6,5	5,5	12,188	11,214	10,348
M 14 × 1,5 keg								14	13,026	12,16			14,188	13,214	12,348
M 16 × 1,5 keg								16	15,026	14,16			16,188	15,214	14,348
M 18 × 1,5 keg								18	17,026	16,16			18,188	17,214	16,348
M 20 × 1,5 keg								20	19,026	18,16			20,188	19,214	18,348
M 22 × 1,5 keg								22	21,026	20,16			22,188	21,214	20,348
M 24 × 1,5 keg								24	23,026	22,16			24,188	23,214	22,348
M 26 × 1,5 keg								26	25,026	24,16			26,188	25,214	24,348
(M 27 × 1,5 keg)								27	26,026	25,16			27,188	26,214	25,348
M 30 × 1,5 keg								30	29,026	28,16			30,188	29,214	28,348

(continued)

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Table 2 (concluded)

Dimensions at reference plane and Dimensions at gauge plane

Thread size	Pitch, P	Useful thread length, L1		Maximum height of thread, h3		Dimension a		Thread dimensions at gauge plane			Gauge length b		Thread dimensions
		Standard design	Short design	Standard design	Short design	Standard design	Short design	Major diameter, d	Pitch diameter, d2	Minor diameter, d3	Standard design	Short design	d	d2	d3
(M 33 × 1,5 keg)	1,5	10,5	9	1,014	0,983	4,5	3,4	33	32,026	31,16	8	6,9	33,219	32,245	31,379
M 36 × 1,5 keg								36	35,026	34,16			36,219	35,245	34,379
M 38 × 1,5 keg								38	37,026	36,16			38,219	37,245	36,379
(M 39 × 1,5 keg)								39	38,026	37,16			39,219	38,245	37,379
M 42 × 1,5 keg								42	41,026	40,16			42,219	41,245	40,379
M 45 × 1,5 keg								45	44,026	43,16			45,219	44,245	43,379
M 48 × 1,5 keg								48	47,026	46,16			48,219	47,245	46,379
M 52 × 1,5 keg	2	12	10	1,321	1,290	5	4	52	51,026	50,16	9	8	52,219	51,245	50,379
M 27 × 2 keg								27	25,701	24,546			27,25	25,951	24,796
M 30 × 2 keg								30	28,701	27,546			30,25	28,951	27,796
M 33 × 2 keg								33	31,701	30,546			33,25	31,951	30,796
M 36 × 2 keg								36	34,701	33,546			36,25	34,951	33,796
M 39 × 2 keg								39	37,701	36,546			39,25	37,951	36,796
M 42 × 2 keg								42	40,701	39,546			42,25	40,951	39,796
M 45 × 2 keg	13	11,5	1,342	1,302	6	4,8	45	43,701	42,546	10	8,8	45,25	43,951	42,796
M 48 × 2 keg							48	46,701	45,546			48,25	46,951	45,796
M 52 × 2 keg							52	50,701	49,546			52,25	50,951	49,796
M 56 × 2 keg							56	54,701	53,546			56,25	54,951	53,796
M 60 × 2 keg							60	58,701	57,546			60,25	58,951	57,796

Bracketed sizes should be avoided where possible.

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4.2 Parallel internal threads

Parallel internal threads shall have the basic profile specified in ISO/DIS 68-1. The maximum and minimum material profiles shall be as given in DIN 13-19*).

The nominal sizes of coarse pitch threads shall conform to DIN 13-1*), those of fine pitch threads with pitches of 1 mm or 1,25 mm to DIN 13-5*), with a pitch of 1,5 mm to DIN 13-6*), and those with a pitch of 2 mm, to DIN 13-7*).

Limit deviations shall be as given in ISO/DIS 965-3. Limits of size and the useful length, l₂, shall be as given in table 5 and clause 5, respectively.

The thread designation shall conform to ISO/DIS 965-1.

Example of designation for a metric parallel internal thread (M), with a nominal diameter of 30 mm and a pitch of 2 mm (fine pitch thread), of tolerance class 4H for the pitch diameter and tolerance class 5H for the minor diameter:

Thread DIN 158 M 30 × 2 – 4H 5H

5 Tolerances, limit deviations and limits of size

Parallel internal thread

Taper external thread

Reference plane

Gauge plane

Taper external thread

1) Internally threaded parts shall be capable of receiving external threaded parts up to the useful length, l₁, making full use of dimension a.

2) Assuming a free thread run-out, length l₂ of the internal thread shall not be less than 80 % of l₁.

3) It is recommended that the thread run-out, x, be 1,5 P.

Figure 2: Internal and external threads (notation)

*) At present at the stage of draft.

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