Full spectrum of industrial fastening solutions | Covering both standard and custom parts
Our 321 Stainless Steel Hex Head Bolts are premium metric fasteners designed for high-temperature, corrosion-resistant, and industrial applications. Compared with 304 stainless steel, 321 stainless steel offers better high-temperature stress rupture performance and improved mechanical stability under elevated temperatures.
These bolts are especially suitable for environments where heat resistance, oxidation resistance, and resistance to intergranular corrosion are required. They are widely used in chemical equipment, petroleum machinery, boilers, heat exchangers, exhaust systems, furnace components, diesel engine mufflers, and other demanding industrial applications.
Available in common metric sizes such as M8, M10, M12, and M16, these hex head bolts provide reliable fastening performance for high-temperature and corrosive working conditions.
| Item | Description |
|---|---|
| Product Name | 321 Stainless Steel Hex Head Bolt |
| Material | Stainless Steel 321 |
| Head Type | Hex Head |
| Thread Type | Metric Thread |
| Common Sizes | M8, M10, M12, M16 |
| Surface Finish | Plain Stainless Steel |
| Standard | Metric / Custom Standard Available |
| Application | High-temperature equipment, chemical machinery, boiler systems, exhaust systems |
| Customization | Size, length, thread pitch, packaging, drawing-based production |
Unit: mm
| Size | Pitch | Width Across Flats S | Head Thickness K |
|---|---|---|---|
| M8 | 1.25 | 13 | 5.3 |
| M10 | 1.5 | 16 | 6.8 |
| M12 | 1.75 | 18 | 7.5 |
| M16 | 2.0 | 24 | 10 |
Additional sizes such as M4, M5, M6, M14, M18, M20, M22, M24, M27, M30, M33, and M36 can also be supplied according to customer requirements.
321 stainless steel is a titanium-stabilized stainless steel. It is commonly used in applications where parts must maintain good mechanical properties under high-temperature conditions.
| Material | Main Feature | Recommended Use |
|---|---|---|
| 304 Stainless Steel | Good general corrosion resistance | General machinery, indoor and outdoor use |
| 316 Stainless Steel | Better corrosion resistance, especially in marine environments | Marine, coastal, chemical, humid environments |
| 321 Stainless Steel | Better high-temperature stability and resistance to intergranular corrosion | Heat exchangers, boilers, exhaust pipes, furnace parts |
For applications involving heat, exhaust gas, chemical equipment, or thermal cycling, 321 stainless steel bolts are a reliable choice.
| Industry / Equipment | Typical Use |
|---|---|
| Chemical Industry | Equipment exposed to corrosive and high-temperature environments |
| Coal Industry | Open-air machinery and heat-resistant assemblies |
| Petroleum Industry | Oil and gas equipment, pipelines, combustion systems |
| Boiler Systems | Boiler housing, pressure vessels, and heating components |
| Heat Exchangers | High-temperature fastening and structural connection |
| Engine Exhaust Systems | Exhaust pipes and muffler components |
| Furnace Equipment | Heating furnace components and spiral welded tube assemblies |
| Diesel Engines | Muffler parts and exhaust-related components |
| Building Materials Industry | Heat-resistant equipment parts |
| Expansion Joints | High-temperature pipeline connection systems |
These 321 stainless steel hex head bolts are commonly used in:
| No. | Application |
|---|---|
| 1 | Oil exhaust gas combustion pipelines |
| 2 | Engine exhaust pipes |
| 3 | Boiler housings |
| 4 | Heat exchangers |
| 5 | Heating furnace components |
| 6 | Muffler parts for diesel engines |
| 7 | Boiler pressure vessels |
| 8 | Chemical trucks |
| 9 | Expansion joints |
| 10 | Spiral welded tubes for furnace pipes and dryers |
The 321 Stainless Steel Hex Head Bolt is designed for demanding industrial environments where ordinary stainless steel fasteners may not provide enough high-temperature stability.
The hex head structure offers excellent torque transmission and easy installation. The stainless steel body provides corrosion resistance, while the 321 grade material helps improve performance in heat-resistant applications.
These bolts are suitable for manufacturers, maintenance teams, engineering contractors, and industrial equipment suppliers who need reliable fasteners for high-temperature and corrosion-resistant working conditions.
Before placing an order, please confirm the following details:
| Required Information | Example |
|---|---|
| Bolt Size | M8, M10, M12, M16 |
| Length | 20mm, 30mm, 50mm, 80mm, customized |
| Thread Type | Full thread or partial thread |
| Material | 321 stainless steel |
| Standard | DIN, ISO, GB, ANSI, or custom drawing |
| Quantity | Small quantity or bulk order |
| Application Environment | High temperature, chemical, outdoor, boiler, exhaust system |
For high-temperature or pressure-related equipment, please confirm the working temperature, load requirement, and applicable industry standard before use.
For better assembly performance, these bolts can be supplied together with:
| Product | Function |
|---|---|
| 321 Stainless Steel Hex Nuts | Matching threaded fastening |
| 321 Stainless Steel Flat Washers | Load distribution and surface protection |
| 321 Stainless Steel Spring Washers | Anti-loosening support |
| Stainless Steel Custom Fasteners | Special industrial assembly requirements |
321 stainless steel is a titanium-stabilized stainless steel with good high-temperature performance and resistance to intergranular corrosion. It is commonly used in heat-resistant industrial applications.
304 stainless steel is suitable for general corrosion-resistant applications. 321 stainless steel has better high-temperature stability and is more suitable for boilers, exhaust systems, heat exchangers, furnace parts, and chemical equipment.
Common sizes include M8, M10, M12, and M16. Other metric sizes from M4 to M36 can also be supplied according to customer requirements.
Yes. 321 stainless steel is commonly used for high-temperature equipment and heat-resistant parts. It performs better than 304 stainless steel in many elevated-temperature environments.
Yes. These bolts are suitable for chemical machinery and equipment requiring corrosion resistance and heat resistance.
Both fully threaded and partially threaded versions can be supplied depending on the size, length, and customer requirements.
Yes. Bolt length can be customized according to drawings, samples, or specific project requirements.
They can be installed with standard wrenches, spanners, or socket tools matching the hex head size.
They can be assembled if the thread size and pitch match. However, for high-temperature or special industrial environments, using matching 321 stainless steel nuts and washers is recommended.
Yes. Bulk orders, OEM packaging, customized specifications, and drawing-based production are available.
321 Stainless Steel Hex Head Bolts M8 M10 M12 M16 are high-temperature resistant metric fasteners designed for chemical, petroleum, boiler, heat exchanger, exhaust system, furnace, and industrial equipment applications. Compared with 304 stainless steel, 321 stainless steel provides better high-temperature mechanical performance and improved resistance to intergranular corrosion, making it suitable for demanding heat-resistant fastening applications.
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Complies with major global standards such as ISO/DIN/GB/ANSI/JIS
Standard parts + customized parts, one-stop solution for all your fastening needs
Tolerance control far exceeds industry standards, ranging from 4.8 to 12.9 grades.
Customization based on provided drawings/samples/working conditions; rapid prototyping and mass production delivery.
Trusted by global manufacturers for fastener solutions
International Organization for Standardization (ISO) standards
German Industrial Standards
Chinese National Standards
American National Standards
Japanese Industrial Standards
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