GOST 11650-80 Self-Tapping Screws with Round Head and Pointed End

Self-Tapping Screws

WITH ROUND HEAD AND POINTED END

For Metal and Plastic

GOST 11650-80*

Self-tapping round head and sharpening end screws for metals and plastics. Construction and dimensions	GOST 11650-80*Supersedes GOST 10621-63, GOST 11650-65, in respect of pointed-end screws

Effective date: 01.01.82.

1. This standard applies to self-tapping screws with round head and pointed end for metal and plastic, product grade B, with nominal thread diameter from 2.5 to 8 mm.

2. The design and dimensions of the screws shall conform to those shown in the drawing and in Tables 1, 2.

Type 1

Type 2

---

• Reference dimension.

Table 1

Dimensions in mm

Nominal thread diameter d		2.5	3	4	5	6	8
Thread pitch P		1.25		1.75	2.0	2.5	3.5
Head diameter D	Nom.	4.5	5.5	7.0	8.5	10.0	13.0
	Tolerance per js15	± 0.24		± 0.29			± 0.35
Head height K	Nom.	1.7	2.1	2.8	3.5	4.2	5.6
	Tolerance per js15	± 0.2			± 0.24
Head sphere radius R₁≈		2.4	2.9	3.6	4.4	5.1	6.6
Radius under head	R, min	0.10		0.20		0.25	0.40
	da, max	3.1	3.6	4.7	5.7	6.8	9.2
Slot width n	Nom.	0.6	0.8	1.0	1.2	1.6	2.0
	Min	0.66	0.86	1.06	1.26	1.66	2.06
	Max	0.80	1.00	1.20	1.51	1.91	2.31
Slot depth t	Min	0.9	1.0	1.6	2.1	2.3	3.3
	Max	1.3	1.4	2.0	2.5	2.7	3.7
Coaxiality tolerance of head relative to shank (2IT14)		0.60		0.72			0.86
Symmetry tolerance of slot relative to shank, diametral (2IT14)		0.50		0.60			0.72
Cross recess number		1		2		3
Cross recess diameter m, max		2.8	3.1	4.2	5.0	6.6	7.7
Cross recess depth h		1.25	1.60	1.75	2.50	2.45	3.65
Gauge penetration depth into cross recess	Max	1.4	1.7	2.0	2.8	3.0	4.2
	Min	1.1	1.4	1.5	2.3	2.5	3.7
Thread run-out, max		0.8			1.0

Note. The cross recess is per GOST 10753-80.

Table 2

mm

Screw length l		Nominal thread diameter d
Nom.	Tolerance per js17	2.5	3	4	5	6	8
6	± 0.75			-	-	-	-
8					-	-	-
10						-	-
12	± 0.90						-
14							-
16
(18)				Standard lengths
20	± 1.05	-
(22)		-	-
25		-	-
30		-	-
35	± 1.25	-	-
40		-	-	-
45		-	-	-
50		-	-	-	-

Note. Lengths l shown in parentheses are not recommended for use.

Designation example:

screw of version 1, diameter 5 mm, length 30 mm, material group 01, without coating, with coarse thread pitch

Screw 5×30.01 GOST 11650-80

Same, version 2, diameter 5 mm, with coarse thread pitch, length 30 mm, made from material group 01, with zinc coating 6 µm thick, chromated

Screw 2-5×30.01.016 GOST 11650-80

3. Technical requirements, thread, inspection methods, acceptance rules, packaging and marking are per GOST 10618-80.

4. The theoretical mass of the screws is given in Reference Appendix 1.

APPENDIX 1

For reference

Theoretical mass of self-tapping screws

Screw length l, mm	Nominal thread diameter d, mm
	2.5	3	4	5	6	8
	Mass of 1000 pcs of steel screws with coarse thread pitch, kg ≈
6	0.32	0.51	-	-	-	-
8	0.37	0.59	1.11	-	-	-
10	0.42	0.67	1.25	2.21	-	-
12	0.47	0.75	1.39	2.43	3.61	-
14	0.52	0.83	1.53	2.67	3.93	-
16	0.57	0.91	1.67	2.91	4.25	5.01
18	0.62	0.99	1.81	3.15	4.57	5.58
20	-	1.07	1.95	3.39	4.89	6.15
22	-	-	2.09	3.63	5.21	6.72
25	-	-	2.30	4.00	5.69	7.57
30	-	-	2.65	4.60	6.49	9.00
35	-	-	3.00	5.20	7.29	10.42
40	-	-	-	5.80	8.09	11.84
45	-	-	-	6.40	8.99	13.25
50	-	-	-	-	9.69	14.68

Equivalent to DIN 7971, ISO 1481.