GOST 7798 Hex Bolts
GOST 7798 Hex Bolts are metric fasteners with a six-sided head designed for wrench or socket installation. The hexagonal head provides convenient access for tightening and loosening, while the threaded shank creates a secure connection with a matching nut or internally threaded component.
For GOST-based assemblies, the correct bolt is selected by considering more than the nominal thread diameter. Bolt length, thread pitch, head dimensions, thread length, material, and property class all affect how the fastener fits and performs in the finished assembly. GOST 7798-70 defines the construction and dimensions of Grade B hexagon head bolts. We can supply these bolts in different metric sizes, carbon steel and stainless steel materials, property classes, and surface finishes according to the required specification or customer drawings.
Specification:
GOST 7798-70 defines the construction and dimensions of Grade B hexagon head bolts for metric fastening applications. The standard covers the main dimensions of the bolt, including thread diameter, head dimensions, bolt length, and thread length, providing a consistent dimensional system for GOST-based assemblies.
The metric thread is based on GOST 24705, with the applicable thread tolerance specified according to the product designation. Mechanical properties and strength classes are determined according to the applicable requirements of GOST 1759.0 and GOST 1759.4 rather than by the dimensional standard alone. Bolts can be supplied in carbon steel or stainless steel according to the required specification. Common options include different property classes for carbon steel and corrosion-resistant stainless steel grades such as A2 and A4. Surface finishes can be supplied according to the material, service environment, and customer requirements.
| Item | Specification |
|---|---|
| Product Type | Hexagon Head Bolt |
| Standard | GOST 7798 |
| Product Grade | B |
| Thread | Metric |
| Thread Standard | GOST 24705 |
| Thread Tolerance | 6g |
| Size Range | M6-M48 |
| Steel Property Class | 4.8,8.8,10.9,12.9 |
| Steel Mechnical Property Standard | GOST 1759.4 |
| Stainless Steel Property Class | A2-70/80 A4-70/80 |
| Stainless Steel Mechanical Property Standard | ISO3506-1 |
| Material | Carbon Steel,Alloy Steel, Stainless Steel |
| Surface Treatment | Black Oxidation,Zinc Plated,HDG |
| Inspection | Dimensions, Thread,Mechanical Property,Coating |
Dimension Chart of GOST 7798 Hex Bolts:
The dimensions of a GOST 7798 hex bolt are defined by the relationship between the thread size, bolt length, head dimensions, and threaded length. The nominal diameter determines the mating nut or threaded hole, while the bolt length and thread length should be selected according to the thickness of the assembled components and the required thread engagement.
The dimension chart includes the main features needed for bolt selection, including nominal diameter, thread pitch, head width across flats, head height, overall length, and thread length.
| Thread Diameter | M6 | M8 | M10 | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M36 | M42 | M48 |
| P | 1 | 1|1.25 | 1.25|1.5 | 1.25|1.5 | 1.5|2 | 1.5|2 | 1.5|2.5 | 1.5|2.5 | 1.5|2.5 | 2|3 | 2|3 | 2|3.5 | 3|4 | 3|4.5 | 3|5 |
| ds | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | 27 | 30 | 36 | 42 | 48 |
| s | 10 | 13 | 16 | 18 | 21 | 24 | 27 | 30 | 34 | 36 | 41 | 46 | 55 | 65 | 75 |
| k | 4 | 5.3 | 6.4 | 7.5 | 8.8 | 10 | 12 | 12.5 | 14 | 15 | 17 | 18.7 | 22.5 | 26 | 30 |
| e min | 10.9 | 14.2 | 17.6 | 19.9 | 22.8 | 26.2 | 29.6 | 33 | 37.3 | 39.6 | 45.2 | 50.9 | 60.8 | 71.3 | 82.6 |
Application of GOST 7798 Hex Bolts:
Machinery and Equipment Assembly
GOST 7798 hex bolts are commonly used to secure machine components, brackets, housings, supports, and mounting parts where a detachable bolted connection is required.
Frames and Fabricated Structures
The bolts are suitable for equipment frames, metal structures, brackets, base plates, and fabricated assemblies where components need to be securely clamped together using matching nuts.
General Metric Fastening
With standardized metric dimensions and a conventional hexagonal head, these bolts can be used in a wide range of industrial and mechanical assemblies where GOST-based fasteners are specified or where a compatible metric bolt is required.