GOST 6402-70 SPRING LOCK WASHERS. SPECIFICATIONS

SPRING LOCK WASHERS

SPECIFICATIONS

GOST 6402-70

(ST SEV 2665-80)

State Standard of the Union of Soviet Socialist Republics

SPRING LOCK WASHERS Specifications Lock washers. Specifications	GOST 6402-70* (ST SEV 2665-80) Supersedes GOST 6402-61

Effective date: 01.01.72. Reviewed in 1982.

This standard applies to spring lock washers for bolts, screws and studs with thread diameters from 2 to 48 mm.

The standard fully complies with ST SEV 2665-80.

1. DESIGN AND DIMENSIONS

1.1. Spring lock washers shall be manufactured in four types:

N - normal, with square cross-section;

T - heavy, with square cross-section;

OT - extra heavy, with square cross-section;

L - light, with rectangular cross-section.

1.2. The design and basic dimensions of washers shall conform to those shown in Fig. 1 and in the table.

Fig. 1

mm

Nominal thread diameter of bolt, screw, stud	d		Washer types										k, (for washer types L and N), max
			Light washers (L)				Normal washers (N)		Heavy washers (T)		Extra heavy washers (OT)
			b		s		b=s		b=s		b=s
	Nom.	Limit deviation	Nom.	Limit deviation	Nom.	Limit deviation	Nom.	Limit deviation	Nom.	Limit deviation	Nom.	Limit deviation
2	2.1	+0.25	0.8	±0.08	0.5	±0.07	0.5	±0.07	0.6	±0.07	-	-	-
2.5	2.6		0.8		0.6		0.6		0.8	±0.08
3	3.1	+0.30	1.0	±0.125	(0.6)		0.8	±0.08	1.0	±0.125
					0.8	±0.08
3.5	3.6		1.0		0.8		1.0	±0.125	-				0.15
4	4.1		1.2		0.8		1.0		1.4
			(1.4)		(1.0)	±0.125	(1.2)
5	5.1		1.2		1.0		1.2		1.6
			(1.6)		(1.2)		(1.4)
6	6.1	+0.58	1.6		1.2		1.4		2.0				0.2
			(2.0)		(1.4)		(1.6)
7	7.2		2.0		1.6		2.0		-
8	8.2		2.0		1.6		2.0		2.5				0.3
			(2.5)
10	10.2	+0.70	2.5		2.0		2.5		3.0		3.5	±0.24
			(3.0)
12	12.2		3.5	±0.15	2.5		3.0		3.5	±0.24	4.0		0.4
14	14.2		4.0		3.0		3.2	±0.15	4.0	±0.24	4.5	±0.24	0.4
							(3.5)
16	16.3		4.5		3.2	±0.15	3.5		4.5		5.0
							(4.0)
18	18.3	+0.84	5.0		3.5		4.0		5.0		5.5
							(4.5)
20	20.5		5.5		(4.0)		4.5		5.5		6.0
							(5.0)
22	22.5		6.0		4.5		5.0		6.0		7.0	±0.29
							(5.5)
24	24.5		6.5	±0.18	4.8		5.5		7.0	±0.29	8.0	±0.29	0.5
			(7.0)		(5.0)		(6.0)
27	27.5		7.0		5.5		6.0		8.0		9.0
			(8.0)				(7.0)	±0.18
30	30.5	+1.00	8.0		6.0		6.5		9.0		10.0		0.8
			(9.0)				(8.0)
33	33.5		10.0		6.0		7.0		-		-
36	36.5		10.0		6.0		8.0		10.0		12.0	±0.35
							(9.0)
39	39.5		10.0		6.0		8.5		-		-	-
42	42.5		12.0	±0.215	7.0	±0.18	9.0		12.0	±0.35
							(10.0)
45	45.5		12.0		7.0		9.5		-	-
48	48.5		12.0		7.0		10.0
							(12.0)	±0.215

Notes:

1. An increase of dimension s within 10% of the nominal size is permitted.

2. Washers with dimensions shown in brackets may be used until 01.01.85, and the letter «u» shall be indicated in their designation.

Examples of designations for a spring lock washer, version 1, for a bolt, screw, stud with a diameter of 8 mm:

normal, made of steel grade 3×13, without coating:

Washer 8 3×13 GOST 6402-70

light, made of steel grade 65G, with a 9 μm chromated cadmium coating:

Washer 8L 65G 029 GOST 6402-70

the same, version 2, with dimensions shown in brackets:

Washer 2U 8L 65G 029 GOST 6402-70

2. Technical requirements

2.1. Spring lock washers shall be made of wire to GOST 11850-72 or other regulatory and technical documentation, from steel grades 65G, 70 and 3×13.

Spring lock washers may also be made of bronze grade BrKMts3-1 to GOST 18175-78 or other non-ferrous alloys.

2.2. The mass of steel washers and the calculated elastic force for steel grade 65G are given in the appendix.

2.3. Steel spring lock washers shall have a hardness of 41.5-49.5 HRCe (HRC40-48); bronze washers not less than 90 HRB. An increase in hardness up to 51.5 HRCe (HRC 50) is permitted for washers made of steel 70.

2.4. The surface of washers shall be free of scale, burrs, cracks and corrosion. Traces of non-removable scale are not a cause for rejection.

On the cut plane, defects that do not affect the performance characteristics of the washers and do not take their dimensions outside the tolerance limits are permitted.

2.5. The ends of washers shall have a flat cut; chipping of metal that does not take the dimension outside the tolerance limits is not a cause for rejection.

The edge formed by the cut plane and the bearing surface of the washer shall be sharp.

2.6. A trapezoidal cross-section of the washer within the height s is not a defect.

The actual thickness is taken as the largest dimension of height s.

2.8. Washers shall be manufactured without coating or with coatings. The types of coatings, their designations and thicknesses are per the regulatory and technical documentation. Other types of coating may be used, per GOST 9.306-85.

2.8a. Technical requirements for coatings are per GOST 9.301-86.

2.9. Washers with a metallic coating applied by cathodic reduction shall be subjected to dehydrogenation.

2.10. The height of spread of washer ends h₁ and h₂, after compressing them three times to a flat state and holding in this state for 24 h, shall be not less than 1.65 of the actual thickness of the washer.

2.11. Washers shall not break or crack when the ends are bent by 45°.

3. ACCEPTANCE RULES AND TEST METHODS

3.1. Acceptance rules are per GOST 17769-83 for products of coarse accuracy (product grade C).

Coating quality control shall be carried out according to a single-stage sampling plan with an inspection level of 5-2 and an acceptable quality level of 4%, per GOST 18242-72.

3.2. From each lot presented for acceptance, washers shall be selected to check:

a) appearance;

b) dimensions;

c) hardness;

d) toughness;

e) spring properties;

f) coating quality.

3.3. The appearance of washers shall be checked by visual inspection with the naked eye or using a magnifying glass with 2.5-3x magnification.

3.4. The dimensions of washers shall be checked with universal measuring instruments or gauges, certified together with the measurement procedures in the manner established by GOST 8.010-90.

3.5. Hardness determination is per GOST 9013-59. The distance from the center of the indentation to the edge of the washer shall equal half of dimension «b». The hardness of washers with nominal diameters from 2 to 5 mm is not checked. For washers over 6 mm, hardness values reduced by 10% are permitted, provided the requirements of items 2.10 and 2.11 are met.

3.6. For the toughness test, one end of the washer is clamped in a vise, the other end is bent with an adjustable wrench or a slotted lever in the direction of increasing dimensions h₁ and h₂ (Figs. 2, 3, 4). During the test, the dimension h between the vise jaws and the wrench, equal to 0.5(d + 2b), shall be maintained.

3.7. The spring properties of washers shall be tested in the following order:

Fig. 2

Fig. 3

Fig. 4

a) the washers are compressed three times to a flat state;

b) at least 10 spring lock washers, separated from each other by flat washers, are placed on the shank of a bolt of the corresponding diameter and tightened with a nut until the spread ends of the washers are fully compressed.

In this state, the washers are held for 24 h.

3.8. Methods for checking coating quality are per GOST 9.302-88.

3.9. Each lot of washers shall be accompanied by a quality document of the established form, indicating:

the name or trademark of the manufacturer,

the designation of the washers,

test results,

net weight of the lot, kg.

4. PACKAGING AND MARKING

4.1. Temporary corrosion protection, packaging of spring lock washers, and marking of containers are per GOST 18160-72.

Appendix

For reference

MASS OF STEEL WASHERS AND THEIR SPRING PROPERTIES

Nominal thread diameter of bolt, screw, stud	Theoretical mass of 1000 pcs of steel washers, kg				Calculated elastic force of washers made of steel 65G, N
	Washer types				Washer types
	Light (L)	Normal (N)	Heavy (T)	Extra heavy (OT)	Light (L)	Normal (N)	Heavy (T)	Extra heavy (OT)
2	0.030	0.017	0.025	-	7.8	11.8	26.5	-
2.5	0.042	0.030	0.056		14.7	16.7	57.8
3	0.084 (0.061)	0.064	0.105		35.3 (8.8)	38.2	101
3.5	0.094	0.117	-		21.6	71.5	-
4	0.129 (0.190)	0.129 (0.189)	0.273		14.7 (50.0)	52.9 (136)	230
5	0.191 (0.318)	0.228 (0.315)	0.432		28.4 (67.6)	71.5 (158)	252
6	0.378 (0.560)	0.376 (0.487)	0.827		36.3 (81.3)	88.2 (184)	418
7	0.749	0.936	-		92.1	289	-
8	0.827 (1.046)	1.034	1.678		71.5 (69.6)	214	583
10	1.608 (1.940)	2.010	2.984	4.212	114 (113)	339	770	1490
12	3.462	3.450	4.816	6.488	187	499	1000	1774
14	5.487	4.480 (5.355)	7.316	9.509	295	463 (756)	1235	2058
16	7.507	6.084 (8.022)	10.56	13.34	283	495 (990)	1509	2372
18	10.23	8.960 (11.40)	14.62	18.06	305	673 (1254)	1803	2734
20	14.33	12.69 (15.75)	19.70	23.89	434	866 (1539)	2107	3077
22	19.25	17.21 (20.92)	25.66	36.14	597	1107 (1862)	2479	4841
24	24.16 (27.21)	22.68 (27.12)	38.55	51.93	642 (818)	1382 (2225)	3989	7085
27	33.14 (38.15)	30.10 (41.76)	56.67	73.71	928 (911)	1539 (3293)	5459	9055
30	46.14 (52.64)	39.05 (60.87)	79.80	101.1	1029 (1009)	1695 (4606)	7115	11192
33	65.07	49.52	-	-	692	1882	-	16317
36	69.51	70.99 (91.03)	115.9	173.9	566	2773 (4998)	7428
39	73.9	86.37	-	-	469	2999	-	-
42	113.9	103.8 (129.7)	195.2		756	3244 (5488)	11535
45	120.1	123.5	-		643	3489	-
48	126.3	145.4 (215.2)			554	3753 (8879)

Notes:

1. To determine the mass of bronze washers, the mass given in the table should be multiplied by a factor of 1.08.

2. Figures in parentheses show the mass and spring force of washers manufactured with cross-sections corresponding to Table 1.

Corresponds to DIN 127.