GOST 10549-80 Thread Runout. Runouts, Incomplete Threads, Undercuts and Chamfers

GOST 10549-80 establishes the dimensions of the thread runout at tool exit or where the tool has a lead-in section, the dimensions of the incomplete thread when threading to a shoulder, the shape and dimensions of undercuts for thread-forming tool exit, and the dimensions of chamfers — for metric, cylindrical pipe, tapered pipe, 60° taper inch, and trapezoidal threads.

THREAD RUNOUT Runouts, incomplete threads, undercuts and chamfers Screw thread runout. Washout threads, total thread runouts, undercuts and chamfers	GOST 10549-80

Effective date 01.01.82.

The dimensions of runouts and incomplete threads for external metric threads correspond to those shown in Fig. 1, 4 (for cut threads), Fig. 2, 3, 5 (for rolled threads), and in Table 1.

A 60° angle may be used.

Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6

The shape and dimensions of undercuts for external metric threads correspond to those shown in Fig. 6 and in Table 1. The dimensions of chamfers for external metric threads are given in Fig. 1 and in Table 1.

Table 1

Dimensions in millimetres

Thread pitch P	Runout x, max			Incomplete thread a, max		Undercut									Chamfer z
	at tool lead-in angle					Type 1						Type 2		df	when mating with internal thread with type 2 undercut	for all other cases
				normal	reduced	normal			narrow
	20°	30°	45°			f	R	R₁	f	R	R₁	f	R₂
0 ,2	0 ,4	0 ,3	0 ,2	0 ,5	0 ,4	-	-	-	-	-	-	-	-	-	-	0 ,2
0 ,25	0 ,5			0 ,6	0 ,5
0 ,3		0 ,4		0 ,7
0 ,35	0 ,6		0 ,3	0.8	0 ,6									d- 0 ,6		0 ,3
0 ,4	0 ,7	0 ,5		1 ,0	0 ,8	1 ,0	0 ,3	0 ,2
0 ,45	0 ,8													d- 0 ,7
0 ,5	1 ,0	0.6	0 ,4	1 ,6	1.0	1 ,6	0 ,5	0.3	1 ,0	0 ,3	0 ,2			d- 0 ,8		0 ,5
0 ,6	1 ,2	0 ,7												d- 0 ,9
0 ,7	1 ,3	0 ,8	0 ,5	2 ,0	1 ,6	2 ,0			1 ,6	0.5	0.3			d- 1.0
0 ,75	1 ,5													d- 1.2		1 ,0
0 ,8		0 ,9	0.6	3 ,0		3.0	1 ,0	0 ,5
1	1 ,8	1 ,2	0 ,7		2 ,0				2 ,0			3 ,6	2 ,0	d- 1.5	2 ,0
1.25	2 ,2	1 ,5	0 ,9	4 ,0	2 ,5	4 ,0			2 ,5	1 ,0	0 ,5	4 ,4	2 ,5	d- 1.8	2 ,5	1 ,6
1 ,5	2 ,8	1 ,6	1 ,0									4.6		d- 2 ,2	3 ,0
1.75	3 ,2	2 ,0	1 ,2									5 ,4	3 ,0	d- 2 ,5	3 ,5
2	3 ,5	2 ,2	1 ,4	5 ,0	3 ,0	5 ,0	1 ,6		3.0			5 ,6		d- 3 ,0		2 ,0
2 ,5	4 ,5	3 ,0	1 ,6	6 ,0	4 ,0	6 ,0		1 ,0	4 ,0			7 ,3	4 ,0	d- 3 ,5	5 ,0	2 ,5
3	5 ,2	3 ,5	2 ,0									7 ,6		d- 4 ,5	6 ,5
3 ,5	6 ,3	4 ,0	2 ,2	8 ,0	5 ,0	8 ,0	2 ,0		5 ,0	1 ,6		10 ,2	5 ,5	d- 5 ,0	7.5
4	7 ,1	4 ,5	2 ,5									10.3		d- 6 ,0	8.0	3.0
4 ,5	8 ,0	5 ,0	3.0	10 ,0	6 ,0	10 ,0	3 ,0		6 ,0		1 ,0	12 ,9	7 ,0	d- 6 ,5	9 ,5
5	9 ,0	5 ,5	3 ,2									13 ,1		d- 7 ,0	10 ,5	4 ,0
5 ,5	10 ,0	6 ,0	3 ,5	12 ,0	8 ,0	12 ,0			8 ,0	2 ,0		15.0	8 ,0	d- 8 ,0
6	11 ,0		4 ,0									16 ,0	8 ,5	d- 9 ,0
Notes: 1. Type 2 grooves reduce stress concentration under the head, but reduce the bearing surface area. 2. The groove dimensions for a given thread pitch may be set according to the nearest tabulated thread pitch. 3. For parts made of high-strength materials with σv > 1400 MPa, and in cases where the groove, besides its technological function, also serves a structural function, grooves not specified by this standard may be used. 4. Runout, incomplete thread, and groove dimensions per GOST 27148 may be used.

The dimensions of runouts and incomplete threads for internal metric threads correspond to those shown in Fig. 7 and in Table 2.

The shape and dimensions of undercuts for internal metric threads correspond to those shown in Fig. 8 and in Table 2. The dimensions of chamfers for internal metric threads are given in Fig. 7 and in Table 2.

A 60° angle may be used.

Fig. 7 Fig. 8

Table 2

In millimetres

Thread pitch P	Runout x, max		Incomplete thread a, max		Undercut									Chamfer z
					Type 1						Type 2		df	when mating with internal thread with type 2 undercut	for all other cases
	normal	reduced	normal	reduced	normal			narrow
					f	R	R₁	f	R	R₁	f	R₂
0 ,2	0 ,5	0.3	1 ,2	1 ,0	-	-	-	-	-	-	-	-	-	-	0 ,2
0 ,25	0 ,6	0 ,4	1 ,5	1 ,2
0.3	0 ,7	0 ,5
0 ,35	0 ,8		2 ,0	1 ,8
0.4	0 ,9	0 ,6													0 ,3
0 ,45	1 ,1	0.7
0 ,5	1 ,2	0 ,8	3 ,5	3 ,0	2 ,0 *	0 ,5	0 ,3	1 ,0 *	0 ,3	0 ,2			d+ 0.3		0 ,5
0 ,6	1 ,5	1 ,0	3 ,5	3 ,0	-	-	-	-	-	-			-
0 ,7	1.8	1 ,2
0 ,75	1 ,9	1 ,3	4 ,0	3 ,2	3 ,0 *	1 ,0	0 ,5	1 ,6 *	0 ,5	0 ,3			d+ 0 , 4		1 ,0
0 ,8	2 ,1	1 ,4			-	-	-	-	-	-			-
1	2 ,7	1 ,8	5 ,0	3 ,8	4 ,0	1 ,0	0 ,5	2.0	0 ,5	0 ,3	3 ,6	2 ,0	d+ 0 ,5	2 ,0
1 ,25	3.3	2 ,2			5 ,0	1 ,6		3.0	1 ,0	0 ,5	4 ,5	2 ,5		2 ,5	1 ,6
1 ,5	4.0	2 ,7	6 ,0	4 ,5	6 ,0		1 ,0				5 ,4	3 ,0	d+ 0 ,7
1 ,75	4.7	3 ,2	7 ,0	5 ,2	7 ,0			4 ,0	1 ,0		6 ,2	3 ,5		3 ,0
2	5 ,5	3 ,7	8 ,0	6 ,0	8.0	2 ,0					6.5		d+ 1 , 0		2 ,0
2.5	7 ,0	4 ,7	10 ,0	7 ,5	10	3 ,0		5 ,0	1 ,6		8 ,9	5 ,0		4 ,0	2 ,5
3	-	5 ,7	-	9 ,0				6.0		1 ,0	11 ,4	6 ,5	d+ 1 , 2
3 ,5		6 ,6		10 ,5				7 ,0			13 ,1	7 ,5		5 ,5	3.0
4		7 ,6		12 ,5	12			8 ,0	2 ,0		14 ,3	8 ,0	d+ 1 , 5
4 ,5		8 ,5		14 ,0	14			10	3.0		16 ,6	9 ,5		7 ,0	4.0
5		9 ,5		16 ,0	16						18 ,4	10 ,5	d+ 1 ,8
5 ,5		-		-				12			18 ,7			8 ,0
6											18 ,9		d+ 2 ,0	8 ,5
* Groove width is given for diameters of 6 mm and above. Notes: 1. Type 2 grooves reduce stress concentration under the head. 2. The groove dimensions for a given thread pitch may be set according to the nearest tabulated thread pitch. 3. For parts made of high-strength materials with σv > 1400 MPa, and in cases where the groove, besides its technological function, also serves a structural function, grooves not specified by this standard may be used. 4. Runout, incomplete thread, and groove dimensions per GOST 27148 may be used.

The dimensions of runouts, incomplete threads, undercuts and chamfers for cylindrical pipe threads correspond to those shown in Fig. 9, 10 and in Table 3, 4.

For external threads

Fig. 9

For internal threads

Fig. 10

Table 3

Dimensions in millimetres

Thread size designation	Number of pitches per 25.4 mm length	Runout x, max, at tool lead-in angle		Incomplete thread a, max		Undercut							Chamfer z
				normal	reduced	normal			narrow			df
						f	R	R ₁	f	R	R ₁
		20 °	30 °
¹/₃	28	1 ,6	1 ,0	2 ,5	1 ,6	2 ,5	1.0	0 ,5	1 ,6	0 ,5	0 ,3	8.0	1 ,0
¹/₁₆												6 ,0
¹/₄	19	2 ,4	1 ,5	4 ,0	2 ,5	4 ,0			2 ,5	1 ,0	0 ,5	11 ,0	1 ,6
³/₈												14 ,5
¹/₂	14	3 ,2	2 ,0	5 ,0	3 ,0	5.0	1.6		3 ,0			18 ,0	2 ,0
⁵/₈												20 ,0
³/₄												23 ,5
⁷/₈												27 ,0
1	11	4 ,1	2 ,5	6 ,0	4 ,0	6 ,0		1 ,0	4 ,0			29 ,5	2 ,5
1¹/₈												34 ,0
1¹/₄												38 ,0
1³/₈												40 ,5
1¹/₂												44 ,0
1³/₄												50 ,0
2												56 ,0
2¹/₄												62 ,0
2¹/₂												71 ,5
2³/₄												78 ,0
3												84 ,0
3¹/₂												96 ,5
3¹/₄												90 ,5
4												109 ,0
4¹/₂												122 ,0
5												134 ,5
5¹/₂												147 ,0
6												160 ,0

Table 4

Dimensions in millimetres

Thread size designation	Number of pitches per 25.4 mm length	Runout x, max		Incomplete thread a, max		Undercut							Chamfer z
		normal	reduced	normal	reduced	normal			narrow			df
						f	R	R ₁	f	R	R ₁
¹/₈	28	2 ,2	1 ,4	4	2 ,5	4	1 ,0	0 ,5	2 ,5	10	0 ,5	10 ,0	1 ,0
¹/₁₆												8 ,0
¹/₄	19	3 ,3	2 ,0	5	3.0	5	1 ,6		3 ,0			13 ,5
³/₈												17.0
¹/₂	14	4 ,8	3 ,0	8	5 ,0	8	2 ,0	1 ,0	5 ,0	1 ,6	0 ,5	21 ,5	1.6
⁵/₈												23.5
³/₄												27 ,0
⁷/₆												31 ,0
1	11	6 ,0	4 ,0	10	6 ,0	10	3.0		6 ,0		1 ,0	34.0
1¹/₈												39 ,0
1¹/₄												43 ,0
1³/₈												45 ,0
1¹/₂												48 ,5
1³/₄												54 ,5
2												60 ,5
2¹/₄												66 ,5
2¹/₂												76 ,0
2³/₄												82 ,5
3												89 ,0
3¹/₂												101 ,0
3¹/₄												95 ,0
4												114 ,0
4¹/₂												126 ,5
5												139 ,0
5¹/₂												152 ,0
6												165 ,0
Note. The width of narrow undercuts may be reduced to 1.5 pitch.

The dimensions of runouts, incomplete threads, undercuts and chamfers for tapered pipe threads per GOST 6211 correspond to those shown in Fig. 11 and in Table 5.

Fig. 11

Table 5

Dimensions in millimetres

Thread size designation	Number of pitches per 25.4 mm length	External thread						Internal thread						Chamfer z
		Runout x, at tool lead-in angle of 20°, max	Incomplete thread a, max	Undercut				Runout x, max	Incomplete thread a, max	Undercut
				f	R	R₁	df			f	R	R₁	df
¹/₈	28	2 ,0	3 ,5	2	0 ,5	0 ,3	8.0	3.0	5 ,5	3	1 ,0	0 ,5	10 ,0	1 ,0
¹/₁₆							6 ,0						8 ,0
¹/₄	19	3 ,0	5 ,0	3	1.0	0 ,5	11 ,0	4 ,0	8 ,0	5	1 ,6		13 ,5	1 ,6
³/₈							14 ,0						17 ,0
¹/₂	14	3 ,5	6 ,5	4			18 ,0	5 ,5	11 ,0	7			21 ,5
³/₄							23 ,5						27 ,0
1		4 ,5	8 ,0	5	1 ,6		29 ,5	7 ,0	14 ,0	8	2 ,0	1 ,0	34 ,0	2 ,0
1¹/₄							38 ,0						42 ,5
1¹/₂							44 ,0						48 ,5
2	11						56 ,0						60 ,0
2¹/₂							71 ,0						76 ,0
3							84 ,0						88 ,5
3¹/₂							9 ,8						101.2
4							109 ,0						114 ,0
5							134 ,5						139 ,5
6							160 ,0						165 ,0
Note. The width of narrow undercuts for internal threads may be reduced to 1.5 pitch.

The dimensions of runouts, incomplete threads, undercuts and chamfers for the 60° taper inch thread per GOST 6111 correspond to those shown in Fig. 12 and in Table 6.

Fig. 12

Table 6

Dimensions in millimetres

Thread size designation	Number of pitches per 25.4 mm length	External thread						Internal thread						Chamfer z
		Runout x, at tool lead-in angle of 20°, max	Incomplete thread a, max	Undercut				Runout x, max	Incomplete thread a, max	Undercut
				f	R	R₁	df			F	R	R₁	df
¹/₁₆	27	2.5	3.5	2	0.5	0.3	6	3.0	6	3	1.0	0.5	8.5	1.0
¹/₈							8						10.5
¹/₄	18	3.5	5.5	3	1.0	0.5	11	4.0	9	4			14.0	1.6
³/₈							14						17.5
¹/₂	14	4.5	6.0	4			18	5.5	11	6	1.6	1.0	22.0
³/₄							23						27.0
1	11	5.5	7.0	5	1.5		29	6.5	14	7			34.0	2.0
1¹/₄							38						42.5
1¹/₂							44						48.5
2							55						60.5

The dimensions of undercuts and chamfers for external and internal single-start trapezoidal threads correspond to those shown in Fig. 13 and in Table 7.

Fig. 13

Table 7

In millimetres

Thread pitch	Undercut					Chamfer z
	f	R	R ₁	External thread df	Internal thread df
1 ,5	2 ,5	1.0	0 ,5	d- 2 ,0	d+ 1 ,0	1 ,0
2	3			d- 3 ,0		1 ,6
3	5	1 ,6		d- 4 ,2		2 ,0
4	6		1 ,0	d- 5 ,2	d+ 1.1	2 ,5
5	8	2 ,0		d- 7 ,0	d+ 1 ,6	3 ,0
6	10	3 ,0		d- 8 ,0		3 ,5
7	12			d- 9 ,0		4 ,0
8				d- 10 ,2	d+ 1 ,8	4 ,5
9	14			d- 11 ,2		5 ,0
10	16			d- 12 ,5		5 ,5
12	18			d- 14.5	d+ 2 ,1	6 ,5
14	20	5 ,0	2 ,0	d- 16 ,5	d+ 2.5	8 ,0
16	25			d- 19 ,5	d+ 2 ,8	9 ,0
18				d- 22 ,5	d+ 3 ,0	10.0
20				d- 24 ,0		11 ,0
22	30			d- 26 ,0		12 ,0
24				d- 28 ,0	d+ 3 ,5	13 ,0
28	40			d- 32 ,0		16 ,0
32				d- 36 ,5		17 ,0
36	50			d- 45 ,5	d+ 4 ,0	20 ,0
40				d- 44 ,5		21 ,0
44	60			d- 48 ,5		25 ,0
48				d- 52 ,8
Note. For multi-start trapezoidal threads, the undercut width is taken equal to the undercut width of a single-start thread whose pitch equals the lead of the multi-start thread. The dimensions of the other elements are taken from Table 7.

Instead of the undercuts shown in Fig. 9–13 and in Table 3–7, symmetrical undercuts (without chamfer) with a rounding radius of R on both sides may be used where f ≤ 2 mm.

For external cylindrical pipe threads, when threading through or threading to a shoulder, where a normal incomplete thread and a normal undercut width are used, a thread-forming tool with a 20° lead-in angle is recommended; where a reduced incomplete thread and a narrow undercut are used, a tool with a 30° lead-in angle is recommended.

For internal cylindrical pipe threads, when threading to a shoulder, where a normal incomplete thread and a normal undercut width are used, a thread-forming tool with a lead-in length of not more than three pitches is recommended; where a reduced incomplete thread and a narrow undercut are used, a tool with a lead-in length of not more than two pitches is recommended.

Limit deviations of the undercut dimensions df and f are assigned based on the design requirements of the parts being manufactured.

INFORMATIONAL DATA

1. DEVELOPED AND SUBMITTED BY the USSR State Committee for Standards

2. APPROVED AND PUT INTO EFFECT by Decree of the USSR State Committee for Standards dated 09.07.80 No. 3501

3. SUPERSEDES GOST 10549-63

4. REFERENCE REGULATORY AND TECHNICAL DOCUMENTS

Designation of the referenced regulatory document	Clause number
GOST 6211-69	5 , 6
GOST 27148-86	2 , 3

5. The validity period restriction was lifted by Protocol No. 3-93 of the Interstate Council for Standardization, Metrology and Certification (IUS 5-6-93)

6. EDITION with Amendment No. 1, approved in December 1986 (IUS 3-87).