GOST 28778-90 Self-Anchoring Expansion Bolts for Construction

Technical specifications

This standard applies to steel self-anchoring expansion bolts (BSR) with a wedging element (ZE) of climatic design versions U3.1, U3 and UKhL3 per GOST 15150, intended for fastening elements of building structures, pipelines, equipment, etc. to concrete, reinforced concrete and brick structures of buildings and facilities.

1. Technical requirements

1.1. BSR are manufactured in accordance with the requirements of this standard, under technical documentation approved in the prescribed manner.

1.2. Parts of BSR of climatic design version U3.1 are made from steels used for bolts of property class 4.6 and higher per GOST 1759.4, while those of versions U3 and UKhL3 are made from steels used for foundation bolts per GOST 24379.0.

1.3. The design and principal dimensions of BSR correspond to those shown in Fig. 1 and Table 1.

Table 1. Dimensions, mm

BSR size designation	OKP code	Nominal thread diameter d	Head diameter D+1.0	Bolt length L	ZE length H	Theoretical mass per 1000 pcs, kg
M6 ´65	128000 0001	6	9.0	65	45	31.92
M8 ´85	128000 0002	8	11.0	85	60	60.92
M10 ´100	128000 0003	10	13.0	100	70	90.61
M12 ´110	128000 0004	12	15.0	110	75	134.02
M16 ´150	128000 0004	16	19.0	150	100	192.29
M20 ´200	128000 0005	20	23.0	200	125	456.90
M22 ´250	128000 0006	22	25.0	250	150	740.6
M24 ´300	128000 0007	24	27.0	300	180	1159.52

1 — bolt; 2 — ZE; 3 — washer; 4 — nut (Fig. 1)

Subject to technical and economic justification, changes to the length of bolts and ZE are permitted.

Example of a designation for a self-anchoring expansion bolt with thread diameter d = 8 mm, length L = 85 mm, version U3:

BSR 8 × 85 U3 GOST 28778-90

1.4. The design and dimensions of the bolt forming part of BSR correspond to those shown in Fig. 2 and Table 2.

1.5. An increase in length L is permitted with a corresponding increase in thread length l specified in Table 2.

1.6. Requirements for the bolt shank and thread are per GOST 1759.0, GOST 1759.1, GOST 1759.4.

1.7. Thread tolerance class — 6g or 8g per GOST 16093.

1.8. Other requirements are not specified.

Table 2. Dimensions, mm

BSR size designation	d	L	D+1.0	h, max	l	Theoretical mass per 1000 pcs, kg
M6 ´65	6	65	9.0	5	30	16.47
M8 ´85	8	85	11.0	5	35	35.22
M10 ´100	10	1000	13.0	5	45	60.24
M12 ´110	12	110	15.0	5	50	100.18
M16 ´150	16	150	19.0	5	70	152.12
M20 ´200	20	200	23.0	5	100	408.61
M22 ´250	22	250	25.0	5	110	590.58
M24 ´300	24	300	27.0	5	150	1099.52

1.9. The design and dimensions of ZE forming part of BSR correspond to those shown in Fig. 3 and Table 3.

Table 3. Dimensions, mm

BSR size designation	d	D	H	b	t		s	Theoretical mass, 1000 pcs, kg
					Nom.	Limit deviation
M6 ´65	6.2	9.8	45	10	6.0	+3.0	0.6	15.45
M8 ´85	8.2	11.8	60	12	7.0	+3.0	0.8	25.70
M10 ´100	10.2	13.8	70	12	7.0	+3.0	0.8	30.30
M12 ´110	12.2	15.8	75	14	8.0	+5.0	0.8	34.20
M16 ´150	16.2	19.8	100	14	8.0	+5.0	0.9	40.17
M20 ´200	20.2	23.8	125	16	9.0	+6.0	1.0	48.29
M22 ´250	22.2	25.8	150	16	9.0	+6.0	1.0	60.02
M24 ´300	24.2	27.8	180	20	11.0	+8.0	1.2	60.22

1.10. ZE is a spiral wound from strip steel per GOST 503.

1.11. By agreement with the customer, BSR may be coated with zinc chromate plating (Zn. chr.) or cadmium chromate plating (Cd. chr.) per GOST 9.306. Subject to technical and economic justification, other types of metallic anti-corrosion coatings per GOST 9.303 are permitted.

1.12. The design load on BSR must not exceed 0.6 σu (ultimate tensile strength) of the metal from which the bolts are made.

1.13. BSR are supplied assembled: bolt, wedging element, flat washer per GOST 6958, nut per GOST 6402.

1.14. Batch size and type of packaging are subject to agreement with the customer, but not exceeding 1 t.

1.15. Each batch of BSR is accompanied by a quality passport indicating: the document number and date, batch number, net batch mass, and copies of certificates for the materials from which the BSR are made.

1.16. Marking and packaging of BSR are per GOST 18160.

1.17. A label per GOST 2601 is attached to each package.

2. Acceptance

During acceptance of BSR, a sample of at least 10% of the batch volume is inspected. Completeness, appearance, geometric parameters, coating quality and certificates for the materials of BSR parts are checked.

3. Test methods

3.1. The geometric parameters of bolts and ZE are checked using gauges or universal measuring instruments.

3.2. Inspection of the assembled BSR is performed visually by comparison with a reference sample.

3.3. Methods for checking coating quality are per GOST 9.302.

4. Transportation and storage

4.1. BSR may be delivered by any mode of transport.

4.2. Storage of BSR is per storage condition group 2 of GOST 15150.

5. Application instructions

5.1. BSR are installed in load-bearing structures of buildings and facilities made of concrete with a compressive strength class of not less than B15 or grade M150.

5.2. To fasten BSR into a load-bearing structure, a hole is drilled with a depth ensuring that the threaded end of the bolt protrudes sufficiently to fasten the structure, and with a diameter exceeding the diameter of the wedging element by no more than 2 mm (Fig. 4).

5.3. BSR is installed into the drilled hole bolt-head first. Before installation, make sure that the wide-coil side of ZE faces the bolt head.

5.4. A service sleeve is fitted onto the bolt shank. By tapping the free end of the sleeve with a hammer, ZE is driven in until settlement stops (Fig. 5). The sleeve is then removed from the bolt shank.

5.5. Elements of building structures, pipelines, various equipment, etc. are fastened onto the protruding threaded end of the bolt using a washer and a nut (Fig. 6).

5.6. To ensure the load-bearing capacity of BSR, a tightening torque exceeding the design value by 20% is applied to the nut.

Referenced normative documents

Designation of the referenced regulatory document	Clause number	Designation of the referenced regulatory document	Clause number
GOST 2.601-68	1.17	GOST 1759.4-87	1.2 , 1.6
GOST 9302-88	3.3	GOST 6402-70	1.13
GOST 9.303-84	1.11	GOST 6958-78	1.13
GOST 9.306-85	1.11	GOST 15150-69	Introduction, 4.2
GOST 503-81	1.10	GOST 16093-81	1.7
GOST 1769.0-87	1.6	GOST 18160-72	1.16
GOST 1759.1-82	1.6	GOST 24379.0-80	1.2