GOST 7783-81 Cup Nibbed Head Bolts, Product Grade C. Construction and Dimensions

GOST 7783-81 applies to cup nibbed head bolts, product grade C, with nominal thread diameter from 5 to 20 mm. The standard fully corresponds to ST SEV 216-86.

The construction and dimensions of the bolts shall conform to those shown in the drawing in Tables 1 and 2.

Type 1

• The slope of the nib’s side faces must not exceed 5°.

Type 2

d₂ is approximately equal to the pitch diameter of the thread

Table 1

mm

CUP NIBBED HEAD BOLTS, PRODUCT GRADE C Construction and dimensions Cup nibbed head bolts, product grade C. Construction and dimensions	GOST 7783-81* (ST SEV 216-86) Supersedes GOST 7783-73

Example of a designation for a bolt with thread diameter d = 12 mm, coarse thread pitch, tolerance class 8g, length l = 60 mm, property class 3.6, with zinc coating 6 µm thick applied by cathodic reduction, chromated:

Bolt M12´60.36.016 GOST 7783-81

Table 2

mm

Nominal thread diameter d		5	6	8	10	12	16	20
Head diameter D		10	12	16	20	24	32	40
Head height k		4	5	6	7	9.2	11.2	16
Sphere radius R »		6	7	9	10.5	13.3	15.8	21
Diameter of the shoulder or shank d₁ (h15)		5	6	8	10	12	16	20
Guide neck height h, min		2.5	3	4	5	6	8	10
Nib width V		2.0	2.5	3.0	3.2	3.6	4.2	4.7
Nib height W, not less than		1.8	2.0	2.3	2.7	3.2	3.5	4.0
Thread length b	For l ≤ 120	16	18	22	26	30	38	46
	For l > 120	-	-	-	32	36	44	52

Thread — per GOST 24705-81, thread pitch — coarse. Thread runout and incomplete thread — per GOST 27148-86. Bolt ends — per GOST 12414-66.

Radius under head — per GOST 24670-81.

Tolerances and methods of inspection of dimensions and deviations of form and location of surfaces — per GOST 1759.1-82. By agreement between the manufacturer and the customer, bolts may be made with thread tolerance class 6e.

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

The diameter of the plain part of the shank d₁ (type 1) is approximately equal to the pitch or nominal diameter of the thread.

Technical requirements — per GOST 1759.0-87. The mechanical properties of the bolts shall conform to property classes 3.6, 4.6, 4.8, 5.6 and 5.8.

Permitted:

• rounding of the nib edges;
• manufacturing M10 bolts with head diameter D = 19 mm, and M16 bolts with diameter D = 30 mm.

The theoretical mass of bolts is given in the reference appendix.

Appendix (informative)

Bolt length l	Nominal thread diameter d
	5	6	8	10	12	16	20
16				-	-	-	-
20					-	-	-
25							-
30							-
35							-
40							-
45
50
55
60
65
70
75
80
90	-
100	-
110	-	-	-
120	-	-	-
130	-	-	-
140	-	-	-
150	-	-	-
160	-	-	-
170	-	-	-	-	-
180	-	-	-	-	-
190	-	-	-	-	-
200	-	-	-	-	-
Notes. Bolts are manufactured with lengths between the bold lines. Bolts in the range from the upper bold line to the dashed line are manufactured with thread up to the nib.

Bolt length, l, mm	Theoretical mass of 1000 bolts, kg, at nominal thread diameter d, mm, for type 1
	5	6	8	10	12	16	20
16	3.765	6.018	11.23	-	-	-	-
20	4.238	6.694	12.45	19.76	-	-	-
25	4.828	7.539	13.99	22.21	39.27	70.25	-
30	5.418	8.384	15.53	26.64	42.80	76.78	-
35	6.007	9.229	17.07	27.07	46.33	83.31	-
40	6.596	10.074	18.61	29.50	49.86	89.84	-
45	7.185	10.919	20.15	31.93	53.39	96.37	191.4
50	7.774	11.764	21.69	34.36	56.92	102.90	201.6
55	8.363	12.609	23.23	36.79	60.45	109.43	211.8
60	8.952	13.454	24.77	39.22	63.98	115.96	222.0
65	9.541	14.299	26.31	41.65	67.51	122.49	232.2
70	10.130	15.144	27.85	44.08	71.04	129.02	242.4
75	10.719	15.989	29.39	46.51	74.57	135.55	252.6
80	11.308	16.834	30.93	48.94	78.10	142.08	262.8
90	-	17.679	33.98	53.80	85.28	155.10	283.5
100	-	18.524	37.04	58.66	92.46	168.12	304.2
110	-	-	-	63.52	99.64	181.14	324.9
120	-	-	-	68.38	106.82	194.10	345.6
130	-	-	-	73.24	114.00	207.18	366.3
140	-	-	-	78.10	121.18	220.20	387.0
160	-	-	-	82.96	128.36	233.22	407.7
170	-	-	-	-	-	246.24	428.4
180	-	-	-	-	-	259.26	449.1
190	-	-	-	-	-	272.28	469.8
200	-	-	-	-	-	285.30	490.5