GOST 10338-80 Hexagon Head Captive Screws

GOST 10338-80 applies to hexagon head captive screws of product grade B with a nominal thread diameter from 6 to 20 mm.

Table 1

mm

Nominal thread diameter d	6	8	10	12	16	20
Shank diameter d₁ (tolerance)	4.0	5.5	7.0	9.0	11.0	14.0
Thread length b	8	10	12	16	20	25
Width across flats	10	13	17	19	24	30
Head height k	4.0	5.5	7.0	8.0	10.0	13.0
Circumscribed circle diameter, not less than	11.0	14.4	18.9	21.1	26.8	33.6
Radius under head R, not more than	0.4	0.5		0.6	0.8

Table 2

Screw length l, mm	Thread diameter d, mm
	6	8	10	12	16	20
(18)		—	—	—	—	—
20		—	—	—	—	—
(22)				—	—	—
25				—	—	—
(28)					—	—
32					—	—
(36)		Standard lengths			—	—
40					—	—
(45)					—	—
50
(55)
60
(70)
80
(90)	—
100	—

Note. Screw lengths shown in brackets are not recommended for use.

Example of a designation for a screw with thread diameter d = 8 mm, tolerance class 6g, length l = 25 mm, property class 5.8, plain:

Screw M8-6g-25.58 GOST 10338-80

The same, property class 8.8, made of steel grade 35Kh, with a 9 µm zinc coating, chromated:

Screw M8-6g-25.88.35Kh.019 GOST 10338-80

Thread — per GOST 24705—2004, thread pitch — coarse. Thread runout — per GOST 10549—80.

Tolerances and methods for inspecting dimensions and deviations of form and location of surfaces — per GOST 1759.1-82.

Surface defects and inspection methods — per GOST 1759.2—82.

Screw length, mm	Theoretical mass of 1000 steel screws, kg, at nominal thread diameter d, mm
	6	8	10	12	18	20
(18)	4.977	—	—	—	—	—
20	5.174	—	—	—	—	—
(22)	5.372	12.46	22.25	—	—	—
25	5.668	13.02	23.16	—	—	—
(28)	5.964	13.58	24.06	36.05	—	—
32	6.359	14.33	25.27	38.04	—	—
(36)	6.754	15.07	26.48	40.04	—	—
40	7.148	16.02	27.69	42.04	—	—
(45)	7.642	16.76	29.20	44.53	—	—
50	8.135	17.69	30.71	47.03	85.42	156.9
(55)	8.629	18.63	32.23	49.52	89.15	163.0
60	9.122	19.56	33.73	52.00	92.88	169.0
(70)	10.110	21.43	36.76	57.00	100.30	181.1
80	11.100	23.30	39.77	62.00	107.80	193.2
(90)	—	25.17	42.77	67.00	115.30	205.3
100	—	27.04	45.77	72.00	122.80	217.5

Corresponds to DIN 7964.