GOST 7787-81 Deep Countersunk Head Bolts, Product Grade C. Construction and Dimensions

GOST 7787-81 applies to deep countersunk head bolts, product grade C, with a nominal thread diameter of 10 mm.

The construction and dimensions of the bolts shall conform to those shown in the drawing and table.

Table 1

mm

DEEP COUNTERSUNK HEAD BOLTS, PRODUCT GRADE C Construction and dimensions Deep countersunk head bolts, product grade C. Construction and dimensions.	GOST 7787-81* Supersedes GOST 7787-72

Bolt length l	50	55	60	65	70	75	80	90	100	110	120	130	140	150
Thread length b	26											32

Example of a designation for a bolt with thread diameter d = 10 mm, length l = 60 mm, coarse thread pitch, tolerance class 8g, property class 4.8:

Bolt M10 × 60 GOST 7787-81

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

Tolerances and methods for inspecting 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 a thread tolerance class of 6e.

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

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

Technical requirements — per GOST 1759.0-87.

The mechanical properties of the bolts shall correspond to property class 4.8.

Bolts are made with a plain finish.

The theoretical mass of the bolt is given in the informative annex.

Appendix (reference)

Nominal bolt length l, mm	Theoretical mass of 1000 pcs. of bolts, kg	Nominal bolt length l, mm	Theoretical mass of 1000 pcs. of bolts, kg
50	30.50	90	50.04
55	32.94	100	54.92
60	35.39	110	59.81
65	37.83	120	64.69
70	40.27	130	69.58
75	42.71	140	74.46
80	45.16	150	79 , 35