GOST 22356-77 High-Strength Bolts, Nuts and Washers

High-Strength Bolts, Nuts and Washers

GOST 22356-77

State Committee of the USSR for Standards

Moscow

State Standard of the Union of Soviet Socialist Republics

High-strength bolts and nuts and washers. General specifications High strength bolts and nuts and washes. General specifications	GOST 22356-77
By Resolution No. 309 of the USSR State Committee for Standards, Council of Ministers, dated February 7, 1977, the effective date was established

from 01.01.79

Reviewed in 1984. By Resolution No. 400 of Gosstandart dated 27.11.84, the validity period was extended to 01.01.90

This standard applies to high-strength hexagon head bolts, hexagon nuts with thread diameter from 16 to 48 mm, and washers for them. The products are intended for steel building structures (including bridge structures), as well as for metal structures used in heavy engineering.

(Amended edition, Amendment No. 1).

1. TECHNICAL REQUIREMENTS

1.1. High-strength bolts, nuts and washers must be manufactured in accordance with the requirements of this standard, GOST 22353-77 – GOST 22355-77.

(Amended edition, Amendment No. 1).

1.2. High-strength bolts, nuts and washers of climatic design U, placement category 1, should be used in regions with a design temperature of minus 40 °C and above; those of climatic design KhL, placement category 1, should be used in regions with a design temperature from minus 40 °C to minus 65 °C — per GOST 15150-69.

1.3. The mechanical properties and material of bolts and nuts must comply with those specified in Tables 1 and 2.

Table 1

Mechanical properties of bolts

Nominal thread diameter d, mm	Mechanical properties						Steel grade per GOST 4543-71*
	Tensile strength sv, MPa (kgf/mm²)		Brinell hardness, HB, max	Reduction of area j, %, min	Elongation d₅, %, min	Impact toughness (KCU) for KhL-design bolts, MJ/m², min
	designation	max.***
From 16 to 27	1100 (110)	1350 (135)	388	35	8	0.5 (5)	40Kh “select”
	1350 (135)	1700 (170)	480				30×3MF 30×2NMFA**
30	950 (95)	1150 (115)	363				40Kh “select”
	1200 (120)	1550 (155)	415		9		30×3MF 35×2AF**
36	750 (75)	950 (95)	363		8		40Kh “select”
	1100 (110)	1550 (155)	388		9		30×3MF
42	650 (65)	850 (85)	363		8		40Kh “select”
	1000 (100)	1550 (155)			9		30×3MF
48	600 (60)	800 (80)			8		40Kh “select”
	900 (90)	1400 (140)			9		30×3MF

---

• Steel with narrowed carbon content limits is used: from 0.37 to 0.42% for 40Kh “select” steel grade.

** Per standards and technical specifications for materials.

Notes

1. For KhL-design bolts made of 40Kh “select” steel, reduction of area is not less than 40%, hardness is not more than HB 363.

2. The elongation standards apply to bolts of climatic design KhL. For bolts of climatic design U, an elongation 2% lower than specified in the table is permitted.

Table 2

Mechanical properties of nuts

Bolts		Nuts
Nominal thread diameter, mm	Steel grade	Stress from test load, MPa (kgf/mm²), min	Brinell hardness, HB		Steel grade	Standard number
			designation	max.
From 16 to 27	40Kh “select”	1100 (110)	241	341	35, 40, 35Kh, 40Kh	GOST 1050-74; GOST 10702-78; GOST 4543-71
30		950 (95)	229	341
36		750 (75)
42		650 (65)
48		600 (60)
From 16 to 27	30×3MF 30×2NMFA	1350 (135)	241	341	40Kh	GOST 4543-71; GOST 10702-78
From 16 to 27	30×3MF 30×2NMFA	1550 (155)	269	388	30×3MF 40Kh
30	30×3MF 35×2AF	1200 (120)	241	341	40Kh
36	30×3MF	1100 (110)
42		1000 (100)
48		900 (90)

(Amended edition, Amendment No. 1).

1.4. (Deleted, Amendment No. 1).

1.5. By agreement between the customer and the manufacturer, bolts with thread diameter less than 20 mm may be made of 40Kh steel.

1.6. Bolts for railway bridges of northern design must be used with nuts made of 40Kh steel. At the customer’s request, bolts for road and urban bridges of northern design must be used with nuts made of 40Kh steel.

1.7. Washers must be made of the following steel grades: VSt5sp2, VSt5ps2, VSt5Gps2 per GOST 380-71, and 35 and 40 per GOST 1050-74 and GOST 10702-78.

1.8. Washers must have a hardness of HRCe 32 … 46.5.

(Amended edition, Amendment No. 1).

1.9. Bolts must have a torque coefficient of not more than 0.20 and not less than 0.14.

1.10. The following are not permitted in the manufacture of bolts and nuts:

• tears and chipping on the thread surface if their depth exceeds the pitch diameter of the thread and if their total length exceeds a quarter of a turn;
• burrs on the bearing surfaces of bolt heads, and burrs on bolt heads extending beyond the bearing washer.

(Amended edition, Amendment No. 1).

1.11. An increase in the bolt shank diameter of up to 0.25 mm above nominal is permitted over a length of up to 20 mm from the bearing surface of the bolt head.

1.12. Other deviations from the correct geometric shape of bolts and nuts are per GOST 1759-70.

(Amended edition, Amendment No. 1).

1.13. Requirements for bolt microstructure, fracture type, reduction of area in the thread after rupture, and elongation in the thread may be established by agreement between the customer and the manufacturer.

2. ACCEPTANCE RULES

2.1. The manufacturing enterprise must conduct acceptance tests to verify that bolts, nuts and washers comply with the requirements of this standard.

2.2. Bolts must be subjected to the following tests: tensile rupture; tensile testing of specimens; determination of impact toughness; rupture test with an inclined washer (at the customer’s request); determination of torque coefficient; determination of hardness.

(Amended edition, Amendment No. 1).

2.3. Nuts must be subjected to the following tests: test load; determination of torque coefficient; determination of hardness.

2.4. The hardness of washers must be measured.

2.5. Bolts, nuts and washers must be presented for acceptance in batches consisting of products of the same designation, made from steel of a single melt, and heat-treated using the same process.

The weight of a batch of bolts must not exceed 1000 kg, and that of nuts and washers – 500 kg.

2.6. Rules for the acceptance of bolts, nuts and washers by appearance and dimensions are per GOST 17769-83.

2.7. To verify the mechanical properties of bolts, nuts and washers, 5 pieces are sampled from the batch for each type of test. Hardness, torque coefficient and tensile rupture tests may be performed on the same products. If at least one product fails a test, a repeat test must be performed on double the number of products.

The results of repeat tests are final and apply to the entire batch.

(Amended edition, Amendment No. 1).

3. Test methods

3.1. Inspection of the products must be carried out without the use of magnifying instruments.

3.2. Inspection of dimensions, limit deviations of shape and position of surfaces, surface roughness, bolt rupture testing (clause 1.3), and rupture testing with an inclined washer must be carried out per GOST 1759-70. The tensile strength must comply with Table 1 of this standard. The values of design areas and loads used in bolt rupture testing are given in reference Appendix 1.

Note. When testing for rupture, bolts whose length is insufficient for installation in the grips may be tested with a special process nut screwed onto two bolts at once. The height of the process nut must be not less than twice the height of a nut per GOST 22354-77.

3.3. The hardness of bolts and nuts (clause 1.3) must be determined per GOST 9012-59, and of washers (clause 1.8) – per GOST 9013-59.

The hardness of bolts must be checked on the end face of the shank. For bolts with a diameter of up to 24 mm, hardness may be measured on the faces of the head. For bolts with a shank length of more than 200 mm, hardness may be measured on the smooth part of the bolt shank.

The hardness of nuts must be checked on the end surface or on one of the faces.

3.4. Tensile testing of specimens (clause 1.3) must be carried out per GOST 1497-84.

For bolts with a length of 70 mm or more, short cylindrical specimens with a diameter of 10 mm are tested. For bolts with a length of less than 70 mm, short cylindrical specimens with a diameter of 6 mm are tested.

Specimens with the shape and dimensions shown in Fig. 1 may be tested.

d – outer thread diameter; b≥d; l – bolt length.

Fig. 1

3.2 – 3.4. (Revised edition, Amendment No. 1).

3.5. Determination of impact toughness (clause 1.3) must be carried out per GOST 9454-78.

3.6. Specimens for tensile and impact toughness testing (clauses 3.4 and 3.5) must be made from bolts of the batch being accepted or from blank rods for bolts (if the bolt length does not allow a standard specimen to be made) that have undergone heat treatment together with the batch being accepted.

3.7. Testing of nuts under test load (clause 1.3) must be carried out per GOST 1759-70. A table of design areas and loads for testing nuts under test load is given in reference Appendix 1.

3.8. The torque coefficient (clause 1.9) shall be determined using a special device capable of simultaneously recording the bolt tension N and the torque Mkr applied to the nut, with an accuracy of ±5%. The determination procedure is given in recommended Annex 2.

Products that have undergone testing must not be used for repeat testing of this type. Washers may be reused provided that a different surface of the washer contacts the nut.

(Amended edition, Amendment No. 1).

3.9. At least five sets of products (bolt, nut and washer) are taken from each batch for testing. The surface of the products must be clean (free of dirt and rust) and lubricated with mineral oil per GOST 20799-75. The nut must screw onto the bolt freely by hand along the entire length of the bolt thread.

3.10. Reference standards for microstructures and fractures and the test methods for bolts (clause 1.13) shall be approved by the customer and the manufacturer.

4. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

4.1. Each bolt shall be marked with the tensile strength in MPa divided by 10, the manufacturer’s trademark, and the heat number code. Bolts of cold-resistant (KhL) design shall additionally be marked with the letters KhL.

The marking shall be raised and applied to the end face of the bolt head (Fig. 2).

1 – manufacturer’s trademark; bolt tensile strength in MPa, divided by 10; “KhL” design designation 2 – heat number code

Fig. 2

4.2. Other marking requirements are per GOST 1759-70.

4.3. Transportation of products in containers without packing into crates is not permitted.

4.4. The end face of the packing shall indicate: the name or trademark of the manufacturer; the product designation; the batch number; the net weight.

4.5. Each batch shall be accompanied by a certificate indicating: the certificate number; the name of the manufacturer; the product designation; the batch number, heat number, heat number code; the test results; the net weight.

(Amended edition, Amendment No. 1).

4.6. Other rules for packaging of products and marking of packing are per GOST 18160-72.

APPENDIX 1

For reference

VALUES OF STRESS AREAS AND LOADS FOR TENSILE TESTING OF BOLTS AND PROOF LOAD TESTING OF NUTS

Nominal diameter over, mm	Stress area for tensile testing, mm²	Tensile strength, MPa (kgf/mm²)
		600 (60)	650 (65)	750 (75)	800 (80)	850 (85)	900 (90)	950 (95)	1000 (100)	1100 (110)	1150 (115)	1200 (120)	1350 (135)	1400 (140)	1550 (155)	1700 (170)
		Load relative to stress area, kN (tf)
16	157	-	-	-	-	-	-	-	-	173 (17.3)	-	-	212 (21.2)	-	-	267 (26.7)
18	192	-	-	-	-	-	-	-	-	211 (21.1)	-	-	259 (25.9)	-	-	326 (32.6)
20	245	-	-	-	-	-	-	-	-	270 (27.0)	-	-	331 (33.1)	-	-	416 (41.6)
22	303	-	-	-	-	-	-	-	-	333 (33.3)	-	-	409 (40.9)	-	-	515 (51.5)
24	352	-	-	-	-	-	-	-	-	387 (38.7)	-	-	475 (47.5)	-	-	598 (59.8)
27	459	-	-	-	-	-	-	-	-	505 (50.5)	-	-	620 (62.0)	-	-	780 (78.0)
30	560	-	-	-	-	-	-	532 (53.2)	-	-	644 (64.4)	672 (67.2)	-	-	868 (86.8)	-
36	816	-	-	612 (61.2)	-	-	-	775 (77.5)	-	898 (89.8)	-	-	-	-	1264 (126.4)	-
42	1120	-	728 (72.8)	-	-	952 (95.2)	-	-	1120 (112.0)	-	-	-	-	-	1736 (173.6)	-
48	1472	883 (88.3)	-	-	1178 (117.8)	-	1325 (132.5)	-	-	-	-	-	-	2060 ((206.0)	-	-

APPENDIX 2

Recommended

PROCEDURE FOR DETERMINING THE TORQUE COEFFICIENT

1 – electric motor; 2 – gearbox; 3 – bolt under test; 4 – torque wrench; 5 – torque wrench indicator; 6 – dynamometer for measuring bolt tension force; 7 – dynamometer indicator; 8 – device housing; 9 – wrench stop

The lower part of the dynamometer device is hinged to the device housing; the bolt under test (3) is attached through the device housing to the upper part of the dynamometer. A worm gearbox (2) connected to an electric motor (1) is mounted in the upper part of the housing. The gear ratio is selected so that the rotational speed of the housing during operation of the fixture is within 10 rpm. The torque applied to the nut is measured using a removable torque wrench (4) with a recording measuring device (5). As the fixture housing rotates, the free end of the wrench bears against the stop (9).

Calibration of the recording measuring device of the torque wrench is performed using weights suspended from the free end (arm l) of the horizontally secured wrench. Based on the calibration results, a calibration chart is plotted with the coordinates: torque Mkr in N×m (kgf×m) – reading of the wrench’s recording measuring device.

Calibration of the dynamometer device is performed on a tensile testing machine with a calibration chart plotted in the coordinates: bolt tension force in kN (tf) – reading of the dynamometer’s recording measuring device.

The bolt is installed in the fixture with a washer placed under the nut. Using the torque wrench, the bolt is tightened by rotating the nut to the specified tension force, the value of which is selected from the table depending on the nominal diameter of the bolt and its strength level.

Note. Preliminary tensioning of the bolt by tightening the nut with a manual box wrench 250–300 mm long until it stops is permitted.

At the moment the specified bolt tension force, as determined by the measuring device of the dynamometer, is reached, the value of the torque Mkr applied to the nut is recorded using the measuring device of the torque wrench.

Using the obtained values of N and Mkr, the torque coefficient K is determined by the formula:

, where Mkr is the torque applied to the nut to tension the bolt to the specified force, in N×m (kgf×m); N is the bolt tension force in kN (tf); d is the nominal diameter of the bolt in mm.

Nominal thread diameter, mm	Bolt tension force in kN (tf) for determining the torque coefficients of bolts at a strength level in MPa (kgf/mm²)
	600 (60)	650 (65)	750 (75)	900 (90)	950 (95)	1000 (100)	1100 (110)	1200 (120)	1350 (135)	1550 (155)
16	-	-	-	-	-	-	120 (12)	-	140 (14)	160 (16)
18	-	-	-	-	-	-	140 (14)	-	170 (17)	200 (20)
20	-	-	-	-	-	-	180 (18)	-	220 (22)	250 (25)
22	-	-	-	-	-	-	220 (22)	-	270 (27)	320 (32)
24	-	-	-	-	-	-	260 (26)	-	320 (32)	360 (36)
30	-	-	-	-	360 (36)	-	-	450 (45)	-	-
36	-	-	410 (41)	-	-	-	600 (60)	-	-	-
42	-	490 (49)	-	-	-	750 (75)	-	-	-	-
48	590 (59)	-	-	890 (89)	-	-	-	-	-	-

Annexes 1, 2. (Revised edition, Amendment No. 1).