GOST 8878-93 Hex Socket Cone-Point Set Screws, Product Grades A and B. Specifications

The interstate standard GOST 8878-93 establishes specifications for hex socket cone-point set screws, product grades A and B, with nominal diameter d from 1.6 to 24 mm. The requirements of the standard are mandatory. Additional requirements meeting the needs of the national economy are shown in italics.

Foreword

1. DEVELOPED by Gosstandart of Russia

SUBMITTED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification

2. ADOPTED by the Interstate Council for Standardization, Metrology and Certification on October 21, 1993

The following voted in favor of adoption:

Name of state	Name of national standardization body
Republic of Belarus Kyrgyz Republic Republic of Moldova Russian Federation Republic of Tajikistan Turkmenistan Ukraine	Belstandart Kyrgyzstandart Moldovastandart Gosstandart of Russia Tajikstandart Turkmenglavgosinspektsiya Gosstandart of Ukraine

3. By Resolution No. 160 of the Committee of the Russian Federation for Standardization, Metrology and Certification dated June 2, 1994, the interstate standard GOST 8878-93 was put into effect as a state standard of the Russian Federation on January 1, 1995.

4. SUPERSEDES GOST 8878-84

5. REISSUE

Contents

Foreword

1. Sizes

2. Technical requirements

3. Designation

APPENDIX (informative)

INFORMATIONAL DATA

INTERSTATE STANDARD
SET SCREWS WITH CONE POINT AND HEXAGON SOCKET, PRODUCT GRADES A AND B. SPECIFICATIONS Hexgonol socket cone-point set screws. Product grades A and B. Specifications	GOST 8878-93

Effective date 1995-01-01

1. Dimensions

1.1. Screw dimensions shall conform to those shown in the figure and Table 1.

The 120° angle is mandatory for short screws, the length of which is given above the dashed stepped line in Table 1.

The 90° angle applies only to the portion of the point below the minor diameter of the thread for screws with nominal lengths shown below the dashed stepped line in Table 1.

Table 1

In millimeters

Nominal thread diameter, d					1.6	2	2.5	3	4	5	6	8	10	12	16	20	24
Thread pitch, P					0.35	0.4	0.45	0.5	0.7	0.8	1.0	1.25	1.5	1.75	2.0	2.5	3.0
d₁		max.			0	0	0	0	0	0	1.5	2.0	2.5	3.0	4.0	5.0	6.0
df					Minor diameter
e		min.¹)			0.803	1.003	1.427	1.73	2.30	2.87	3.44	4.58	5.72	6.86	9.15	11.43	13.72
S		nom.			0.7	0.9	1.3	1.5	2.0	2.5	3.0	4.0	5.0	6.0	8.0	10.0	12.0
		min.			0.711	0.889	1.270	1.520	2.020	2.520	3.020	4.020	5.020	6.020	8.025	10.026	12.032
		max.			0.724	0.902	1.295	1.545	2.045	2.560	3.080	4.095	5.095	6.095	8.115	10.115	12.142
min		2)			0.7	0.8	1.2	1.2	1.5	2.0	2.0	3.0	4.0	4.8	6.4	8.0	10.0
		3)			1.5	1.7	2.0	2.0	2.5	3.0	3.5	5.0	6.0	8.0	10.0	12.0	15.0
l nom. min	Product grade
	A		B
	min.	max.	min.	max.
2	1.8	2.2	1.5	2.5
2.5	2.3	2.7	2	3
3	2.8	3.2	2.5	3.5
4	3.76	4.24	3.4	4.6
5	4.76	5.24	4.4	5.6
6	5.76	6.24	5.4	6.6
8	7.71	8.29	7.25	8.75
10	9.71	10.29	9.25	10.75
12	11.65	12.35	11.1	12.9							Standard lengths
16	15.65	16.35	15.1	16.9
20	19.58	20.42	18.95	21.05
25	24.58	25.42	23.95	26.05
30	29.58	30.42	28.95	31.05
35	34.5	35.5	33.75	36.25
40	39.5	40.5	38.75	41.25
45	44.5	45.5	43.45	46.25
50	49.5	50.5	48.75	51.25
55	54.4	55.6	53.5	56.5
60	59.4	60.6	58.5	61.5
70	69.4	70.6	68.5	71.5
80	79.4	80.6	78.5	81.5
90	89.3	90.7	88.25	91.75
100	99.3	100.7	98.25	101.75
1) e min = 1.14 s min, except for sizes M1.6; M2; M2.5. 2) Minimum key engagement depth for screws with nominal lengths indicated above the dotted line. 3) Minimum key engagement depth for screws with nominal lengths indicated below the dotted line.

1.2. The theoretical mass of the screws is given in the appendix.

2. Technical requirements

Screws shall be manufactured in accordance with the requirements given in Table 2.

Table 2

Material		Steel	Corrosion-resistant	Non-ferrous alloys
Thread	Tolerance class	5 g6 g for grade 45H; 6 g for other grades
	Standards	GOST 16093, GOST 24705
Mechanical properties	Property class or material group	14H, 22H 33H,45H	21-26	31-35
	Standards	GOST 25556	GOST 1759.0
Tolerances	Product grade	A, B
	Standards	GOST 1759.1
Final surface treatment of product		Plain. Requirements for electroplated coatings per GOST 9.301, GOST 9.303. Screws shall be manufactured with coatings: zinc chromate, nickel, oxide, oil-impregnated, or without coating. Other types of coatings may be used by agreement between the manufacturer and the customer.
Acceptance		Acceptance rules - GOST 17769
Test methods		Dimensions, form and position tolerances of surfaces - GOST 1759.1
		Surface defects - GOST 1759.2
		Mechanical properties
		GOST 25556	GOST 1759.0	GOST 1759.0
Marking and packaging		GOST 1759.0, GOST 18160

3. Designation

Designation examples

Hex socket cone-point set screw, product grade B, thread diameter d = 10 mm, tolerance class 6g, length l = 25 mm, property class 14H, without coating:

Screw M10-6g×25.14H GOST 8878-93

Same, product grade A, property class 45H, made of steel 40Kh with chemical oxide coating, oil-impregnated:

Screw A.M10-6g×25.45H.40Kh.05 GOST 8878-93

Same, made of brass LS59-1, without coating:

Screw A.M10-6g×25.32LS59-1 GOST 8878-93

Appendix

For reference

Table 3 - Mass of screws

Length l, mm	Theoretical mass of 100 pcs of steel screws, kg ≈, at nominal thread diameter d, mm
	1.6	2	2.5	3	4	5	6	8	10	12	16	20	24
2	0.01	0.01
2.5	0.02	0.03	0.03	0.06
3	0.03	0.04	0.05	0.07	0.08
4	0.04	0.06	0.09	0.10	0.11	0.13
5	0.06	0.09	0.13	0.15	0.21	0.29	0.55
6	0.07	0.11	0.16	0.22	0.30	0.44	0.75	1.22
8	0.10	0.16	0.24	0.32	0.46	0.90	1.15	2.05	3.20
10		0.21	0.32	0.43	0.62	0.93	1.38	2.82	4.15	4.65
12			0.40	0.55	0.77	1.18	1.73	3.60	5.38	6.55	10.7
16				0.77	1.08	1.67	2.43	4.12	6.07	9.75	17.0	26.4
20					1.39	2.17	3.14	5.40	8.08	10.69	23.3	34.2	41.70
25						2.79	4.02	6.99	10.60	14.29	24.8	41.4	65.52
30							4.91	8.59	13.10	18.00	31.4	48.2	77.23
35							5.79	10.18	15.63	21.62	38.1	58.5	84.92
40							6.67	11, 77	18.14	25.23	44.8	69.0	95.13
45							7.55	13.37	20.65	28.85	51.4	79.4	110.10
50								14.96	23.17	32.55	58.0	89.8	124.90
55								16.55	25.58	36.17	64.8	100.2	139.88
60								18.14	28.10	39.78	71.4	110.7	155.11
70									33.13	47.10	84.7	131.5	185.06
80										54.42	98.0	152.4	215.00
90											111.4	173.2	245.04
100												194.0	274.78
Note - To determine the mass of screws made of other materials, the mass values given in the table shall be multiplied by the following factor: 0.356 for aluminium alloy; 0.97 for bronze; 1.08 for brass.

INFORMATIONAL DATA

REFERENCE REGULATORY AND TECHNICAL DOCUMENTS

Designation of the referenced regulatory document	Clause number
GOST 9.301-86	2
GOST 9.303-84	2
GOST 1759.0-87	2
GOST 1759.1-82	2
GOST 1759.2-82	2
GOST 16093-2004	2
GOST 17769-83	2
GOST 18160-72	2
GOST 24705-2004	2
GOST 25556-82	2

Corresponds to DIN 914.