GOST R ISO 7049-2012 Self-Tapping Screws

GOST R ISO 7049-2012 applies to self-tapping screws with cylindrical head and spherical top with cross recess, with ST2.2 to ST9.5 thread inclusive.

Normative references

This standard uses references to the following standards:

GOST 9.301-86 Unified system of corrosion and ageing protection. Metallic and non-metallic inorganic coatings. General requirements

GOST 9.303-84 Unified system of corrosion and ageing protection. Metallic and non-metallic inorganic coatings. General requirements for selection

GOST 1759.0-87 Bolts, Screws, Studs and Nuts. Specifications

GOST 1759.1-82 Bolts, screws, studs, nuts and wood screws. Tolerances. Methods of control of dimensions and deviations of form and location of surfaces

GOST 1759.2-82 Bolts, screws and studs. Surface defects and control methods

GOST 10753-86 Cross recesses for screws and wood screws. Dimensions and control methods

GOST 17769-83 Fasteners. Acceptance rules

GOST 18160-72 Fasteners. Packaging. Marking. Transportation and storage

GOST R ISO 1478-93 Thread for self-tapping screws

GOST R ISO 2702-93 Self-tapping steel heat-treated screws. General specifications

Sizes

Screw design and dimensions correspond to those shown in figure 1 and tables 1 and 2.

Figure 1

Table 1

Dimensions in mm

Thread				ST2.2	ST2.9	ST3.5	ST4.2	ST4.8	ST5.5		ST6.3	ST8	ST9.5
P1)				0.8	1.1	1.3	1.4	1.6	1.8		1.8	2.1	2.1
a2), max				0.8	1.1	1.3	1.4	1.6	1.8		1.8	2.1	2.1
da, max				2.8	3.5	4.1	4.9	5.6	6.3		7.3	9.2	10.7
dk			max	4.0	5.6	7.0	8.0	9.5	11.0		12.0	16.0	20.0
			min	3.70	5.30	6.64	7.64	9.14	10.57		11.57	15.57	19.48
k			max	1.6	2.4	2.6	3.1	3.7	4.0		4.6	6.0	7.5
			min	1.40	2.15	2.35	2.80	3.40	3.70		4.30	5.60	7.10
r, min				0.10	0.10	0.10	0.20	0.20	0.25		0.25	0.40	0.40
rf				3.2	5.0	6.0	6.5	8.0	9.0		10.0	13.0	16.0
Recess size				0	1	2			3			4
Cross recess	Type H	m	max	1.9	3.0	3.9	4.4	4.9	6.4		6.9	9.0		10.1
		gauge engagement depth	min	0.85	1.40	1.40	1.90	2.40	2.60		3.10	4.15		5.20
			max	1.2	1.8	1.9	2.4	2.9	3.1		3.6	4.7		5.8
	Type Z	m	max	2.0	3.0	4.0	4.4	4.8	6.2		6.8	8.9		10.1
		gauge engagement depth	min	0.95	1.45	1.50	1.95	2.30	2.55		3.05	4.05		5.25
			max	1.20	1.75	1.90	2.35	2.75	3.00		3.50	4.50		5.70
y3)		Type C		2.0	2.6	3.2	3.7	4.3	5.0	6.0		7.5		8.0
		Type F		1.6	2.1	2.5	2.8	3.2	3.6	3.6		4.2		4.2
1) Thread pitch. 2) Distance from the head bearing surface to the first full thread. 3) Length of incomplete thread (for reference).

Table 2

Dimensions in mm

Technical specifications

Table 3

Material	Steel	GOST R ISO 2702
Thread	GOST R ISO 1478
Mechanical properties	GOST R ISO 2702
Tolerances	Product grade A	GOST 1759.1
Cross recess	GOST 10753
Product surface	Plain and coated	GOST 1759.0, GOST 9.301, GOST 9.303
	Surface discontinuities	GOST 1759.2
Acceptance	GOST 17769
Packaging of screws, container marking, transportation and storage	GOST 18160

Designation example

Self-tapping screw with cylindrical head and spherical top, type Z cross recess, thread size ST3.5, nominal length l=16 mm, end type C, plain:

Screw ST3.5x16-C-Z GOST R ISO 7049-93

Self-tapping screw with cylindrical head and spherical top, type H cross recess, thread size ST4.2, nominal length l=22 mm, end type F, with 6 µm zinc coating, chromated:

Screw ST4.2x22.016-F-H GOST R ISO 7049-93

The theoretical mass of screws is given in the appendix.

APPENDIX A

(informative)

Table A.1

Thread	ST2.2	ST2.9	ST3.5	ST4.2	ST4.8	ST5.5	ST6.3	ST8	ST9.5
Screw length l, mm	Theoretical mass of 1000 pcs of steel type C screws, kg
4.5	0.192	-	-	-	-	-	-	-	-
6.5	0.237	0.522	-	-	-	-	-	-	-
9.5	0.306	0.671	0.970	1.445	2.234	-	-	-	-
13.0	0.387	0.810	1.175	1.734	2.623	3.321	4.531	-	-
16.0	0.455	0.929	1.350	1.982	2.948	3.748	5.103	9.841	18.254
19.0	-	1.048	1.526	2.230	3.272	4.177	5.674	10.774	19.670
22.0	-	-	1.701	2.478	3.597	4.605	6.246	11.706	21.086
25.0	-	-	1.877	2.725	3.921	5.033	6.817	12.638	22.502
32.0	-	-	-	3.303	4.678	6.031	8.151	14.814	25.806
38.0	-	-	-	-	-	6.887	9.294	16.679	28.638
45.0	-	-	-	-	-	-	-	18.854	31.943
50.0	-	-	-	-	-	-	-	20.408	34.303

Corresponds to ISO 7049.