GOST 27148-86 Fasteners. Thread run-out. Run-outs, incomplete threads and undercuts. Dimensions

INTERSTATE STANDARD

Fasteners	GOST 27148-86
THREAD RUNOUT, UNDERCUTS, INCOMPLETE THREADS AND GROOVES
Sizes
Fasteners. Screw thread run-out. Washout threads, total thread run-outs and undercuts. Dimensions

Effective date 01.01.88

This standard applies to fasteners with metric thread per GOST 8724 and establishes the dimensions of thread runouts made by cutting or rolling, the dimensions of incomplete threads when threading up to a shoulder, and the shape and dimensions of grooves for the thread-forming tool runout.

The standard may also be applied to metric-thread products that are not fasteners.

For products designed before January 1, 1988, it is permitted to apply the runouts, incomplete threads and grooves per GOST 10549.

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

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Table 1

mm

Thread pitch P	Nominal thread diameter with coarse pitch d	Runout x, max		Incomplete thread a, max			Undercut
		normal ≈2.5P	short ≈1.25 P	normal ≈3 P	short ≈2P	long ≈4 P	dg h13*	g₁, min	g₂, max ≈3P	r ≈ 0.5P
0.2	0.8	0.5	0.25	0.6	0.4	0.8	d - 0.3	0.32	0.6	0.1
0.25	1; 1.2	0.6	0.3	0.75	0.5	1	d - 0.4	0.4	0.75	0.12
0.3	1.4	0.75	0.4	0.9	0.6	1.2	d - 0.5	0.5	0.9	0.16
0.35	1.6; 1.8	0.9	0.45	1.05	0.7	1.4	d - 0.6	0.6	1.05	0.16
0.4	2	1	0.5	1.2	0.8	1.6	d - 0.7	0.6	1.2	0.2
0.45	2.2; 2.5	1.1	0.6	1.35	0.9	1.8	d - 0.7	0.7	1.35	0.2
0.5	3	1.25	0.7	1.5	1	2	d - 0.8	0.8	1.5	0.2
0.6	3.5	1.5	0.75	1.8	1.2	2.4	d - 1	0.9	1.8	0.4
0.7	4	1.75	0.9	2.1	1.4	2.8	d - 1.1	1.1	2.1	0.4
0.75	4.5	1.9	1	2.25	1.5	3	d - 1.2	1.2	2.25	0.4
0.8	5	2	1	2.4	1.6	3.2	d - 1.3	1.3	2.4	0.4
1	6; 7	2.5	1.25	3	2	4	d - 1.6	1.6	3	0.6
1.25	8	3.2	1.6	3.75	2.5	5	d - 2	2	3.75	0.6
1.5	10	3.8	1.9	4.5	3	6	d - 2.3	2.5	4.5	0.8
1.75	12	4.3	2.2	5.25	3.5	7	d - 2.6	3	5.25	1
2	14; 16	5	2.5	6	4	8	d - 3	3.4	6	1
2.5	18; 20; 22	6.3	3.2	7.5	5	10	d - 3.6	4.4	7.5	1.2
3	24; 27	7.5	3.8	9	6	12	d - 4.4	5.2	9	1.6
3.5	30; 33	9	4.5	10.5	7	14	d - 5	6.2	10.5	1.6
4	36; 39	10	5	12	8	16	d - 5.1	7	12	2
4.5	42; 45	11	5.5	13.5	9	18	d - 6.4	8	13.5	2
5	48; 52	12.5	6.3	15	10	20	d - 1	9	15	2.5
5.5	56; 60	14	7	16.5	11	22	d - 1.1	11	17.5	3.2
6	64; 68	15	7.5	18	12	24	d - 8.3	11	18	3.2

• For d ≤ 3 mm, h12.

Notes:

1. Nominal runout and normal groove — for all products of product grades A, B and C.

2. Normal incomplete thread — for product grade A, long incomplete thread — for product grades B and C.

3. Short runout and short incomplete thread — for products that, for technical reasons, require a reduced thread runout.

4. It is permitted to make grooves with the dimensions specified in the appendix.

5. The shape and dimensions of grooves for external metric thread shall conform to those shown in Fig. 6 and Table 1.

Fig. 6

3. The dimensions of runouts, incomplete threads and grooves for internal metric thread shall conform to those shown in Fig. 7 and 8 and Table 2.

Fig. 7

Fig. 8

Table 2

mm

Thread pitch P	Nominal thread diameter with coarse pitch d	Runout x, max			Incomplete thread a, min			Undercut
		normal	short	long	normal	short	long	g₁, min		g₂, max ≈3 P		dgH13	R ≈ 0.5P
								normal	narrow	normal	narrow
0.2	0.8	0.4	0.3	0.8	1.6	1.0	2.0	0.8	0.5	1.2	0.9	d + 0.1	0.1
0.25	1; 1.2	0.5	0.3	1.0	1.8	1.2	2.5	1.0	0.6	1.4	1.0	d + 0.1	0.12
0.3	1.4	0.6	0.4	1.2	2.0	1.2	2.8	1.2	0.75	1.6	1.25	d + 0.1	0.16
0.35	1.6; 1.8	0.7	0.4	1.4	2.2	1.5	3.2	1.4	0.9	1.9	1.4	d + 0.2	0.16
0.4	2	0.8	0.6	1.6	2.5	1.5	3.5	1.6	1.0	2.2	1.6	d + 0.2	0.2
0.45	2.2; 2.5	0.9	0.6	1.8	3.0	2.0	4.0	1.8	1.1	2.4	1.7	d + 0.2	0.2
0.5	3	1.0	0.8	2.0	3.0	2.0	5.0	2.0	1.25	2.7	2.0	d + 0.3	0.2
0.6	3.5	1.2	0.8	2.4	3.5	2.5	5.5	2.4	1.5	3.3	2.4	d + 0.3	0.4
0.7	4	1.4	1.0	2.8	3.5	2.5	6.0	2.8	1.75	3.8	2.75	d + 0.3	0.4
0.75	4.5	1.5	1.0	3.0	4.0	2.5	7.0	3.0	1.9	4	2.9	d ± 0.3	0.4
0.8	5	1.6	1.2	3.2	4.0	2.5	8.0	3.2	2.0	4.2	3.0	d + 0.3	0.4
1	6; 7	2.0	1.5	4.0	6.0	4.0	10.0	4.0	2.5	5.2	3.7	d + 0.5	0.6
1.25	8	2.5	1.8	5.0	8.0	4.0	12.0	5.0	3.2	6.7	4.9	d + 0.5	0.6
1.5	10	3.0	2.0	6.0	9.0	4.0	13.0	6.0	3.8	7.8	5.6	d + 0.5	0.8
1.75	12	3.5	2.5	7.0	11.0	5.0	16.0	7.0	4.3	9.1	6.4	d + 0.5	1.0
2	14; 16	4.0	3.0	8.0	11.0	5.0	16.0	8.0	5.0	10.3	7.3	d + 0.5	1.0
2.5	18; 20; 22	5.0	3.5	10.0	12.0	6.0	18.0	10.0	6.3	13	9.3	d + 0.5	1.2
3	24; 27	6.0	4.0	12.0	15.0	7.0	22.0	12.0	7.5	15.2	10.7	d + 0.5	1.6
3.5	30; 33	7.0	5.0	14.0	17.0	8.0	25.0	14.0	9.0	17.7	12.7	d + 0.5	1.6
4	36; 39	8.0	6.0	16.0	19.0	9.0	28.0	16.0	10.0	20.0	14.0	d + 0.5	2.0
4.5	42; 45	9.0	6.0	18.0	23.0	11.0	33.0	18.0	11.0	23.0	16.0	d + 0.5	2.0
5	48; 52	10.0	7.0	20.0	26.0	12.0	37.0	20.0	12.5	26.0	18.5	d + 0.5	2.5
5.5	56; 60	11.0	8.0	22.0	28.0	13.0	40.0	22.0	14.0	28.0	20.0	d + 0.5	3.2
6	64; 68	12.0	9.0	24.0	28.0	13.0	42.0	24.0	15.0	30.0	21.0	d + 0.5	3.2

Appendix

For reference

PERMISSIBLE GROOVE DIMENSIONS

Table 3

mm

Thread pitch P	Undercut
	Narrow (g₂ ≈ 2.5 P)		Wide (g₂ ≈ 3.5 P)
	g₁, min	g₂, max	g₁, min	g₂, max
0.2	0.25	0.5	0.45	0.7
0.25	0.25	0.6	0.55	0.9
0.3	0.3	0.75	0.6	1.05
0.35	0.4	0.9	0.7	1.2
0.4	0.5	1.0	0.8	1.4
0.45	0.5	1.1	1.0	1.6
0.5	0.5	1.25	1.1	1.75
0.6	0.6	1.5	1.2	2.1
0.7	0.8	1.75	1.5	2.45
0.75	0.9	1.9	1.6	2.6
0.8	0.9	2.0	1.7	2.8
1	1.1	2.5	2.1	3.5
1.25	1.5	3.2	2.7	4.4
1.5	1.8	3.8	3.2	5.2
1.75	2.1	4.3	3.9	6.1
2	2.5	5.0	4.5	7
2.5	3.2	6.3	5.6	8.7
3	3.7	7.5	6.7	10.5
3.5	4.7	9	7.7	12
4	5.0	10	9.0	14
4.5	5.5	11	10.5	16
5	6.5	12.5	11.5	17.5
5.5	7.5	14	12.5	19
6	8.0	15	14.0	21

INFORMATIONAL DATA

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

2. APPROVED AND PUT INTO EFFECT by Resolution of the USSR State Committee for Standards dated 11.12.86 No. 3780

3. The standard fully complies with ST SEV 214-86

The standard fully complies with international standards ISO 3508-76 and ISO 4755-83

4. INTRODUCED FOR THE FIRST TIME

5. REFERENCE REGULATORY AND TECHNICAL DOCUMENTS

Designation of the referenced regulatory document	Clause, subclause, item, appendix number
GOST 8724-2002 GOST 10549-80	Introductory part

6. REISSUED 2006