Din933 Din931 Stainless Steel 321 Half Thread Hex Bolt Hex Head Bolt Hexagonal Bolt Special Material Hex Bolt

This product is a 321 stainless steel half-threaded external hexagonal bolt (also known as 1Cr18Ni9Ti stainless steel hexagonal head screw, high-temperature resistant external hexagonal bolt). It is a high-performance industrial fastener specially designed for harsh working conditions such as medium-high temperature, corrosion, and high vibration. The product is made of 321 austenitic stainless steel (national standard designation 1Cr18Ni9Ti, ASTM A193 B6T) as the core base material. It is formed through precise hot upsetting, rolling threads, solution heat treatment, and passivation anti-rust processes. It is based on 304 stainless steel and contains titanium elements, offering excellent corrosion resistance and superior high-temperature resistance and intergranular corrosion resistance. It is equipped with a standard external hexagonal + half-thread structure, providing stable, long-lasting, and safe connection and fastening solutions for fields such as boilers, chemical industries, automotive exhaust, aerospace, etc.

321 stainless steel exclusive material, with excellent resistance to high temperature and intergranular corrosion

321 stainless steel is a titanium-containing austenitic stainless steel. The addition of titanium elements completely solves the intergranular corrosion problem of ordinary stainless steel at temperatures ranging from 400 to 900 degrees Celsius, allowing it to work stably in medium-high temperature environments of around 800 degrees Celsius; it also has excellent acid and alkali resistance, salt spray resistance, and anti-corrosion properties, and can be used in complex environments such as chemical plants, coastal areas, and humid conditions for long-term use. It is non-magnetic, non-toxic, and harmless, meeting the standards for high-end industrial use.

Standard hexagon + semi-thread structure, universal installation + protective thread dual advantages

Designed strictly in accordance with GB/T 5782 (ISO 4014, DIN 931) international standards, the standard hexagonal head shape is suitable for universal wrenches, sockets, and power tools, allowing for quick installation without the need for special tools; the semi-thread design enables a precise transition between the bare rod section and the threaded section, preventing the bare rod section from being damaged by the thread squeezing when tightened, while also dispersing stress and enhancing the fatigue resistance of the bolt, perfectly adapting to connection scenarios requiring bare rod positioning and high load.

High-precision rolled threads, tight engagement, anti-loosening, and shock resistance

Using a fully automatic rolled thread process, the thread accuracy reaches grade 6g, with full teeth, no burrs, and no slippage, ensuring a tight engagement with the nut / threaded hole, uniform force, excellent anti-loosening and shock resistance performance, capable of withstanding long-term vibration and impact loads, avoiding the risk of loosening and detachment; the rolling process also enhances the surface hardness and fatigue resistance of the product, with a service life far exceeding that of cutting processing bolts.

Solution annealing process, dual improvement of performance and lifespan

The product undergoes 1000-1100℃ solution heat treatment + rust prevention treatment to eliminate internal stress, optimize the microstructure, and maximize the anti-intergranular corrosion, high-temperature resistance, and mechanical properties; the surface has high smoothness, no oxide scale, no scratches, strong appearance texture, and enhanced corrosion resistance, reducing stress concentration, and extending the product lifespan.

Full specification coverage, customized service

Covering the full range of M6-M30 threaded specifications, with lengths ranging from 20mm to 300mm, all categories are supplied, and non-standard customization is supported. Customization of special lengths, special threads, full tooth / semi-tooth structure of the external hexagon bolts can be provided according to customer requirements, meeting the personalized fastening needs of high-temperature equipment and special working conditions.

High-temperature resistant and anti-intergranular corrosion, specially designed for medium-high temperature conditions: 321 stainless steel is added with titanium elements, which perfectly addresses the problems of intergranular corrosion and strength reduction at high temperatures, and is suitable for medium-high temperature scenarios such as boilers, automotive exhaust, and chemical industries, fundamentally solving the problem of bolt failure.

Half-thread structure, the preferred choice for high-load scenarios: The half-thread design distributes stress, protects the threads, enhances fatigue resistance, and ensures a more stable connection under the same strength. It is suitable for connecting steel structures and equipment in scenarios that require optical shaft positioning and high loads.

Easy installation, versatile: Standard external hexagonal structure, compatible with common tools, can directly replace ordinary bolts of the same specification, without changing the original assembly process. High installation efficiency, suitable for all industry scenarios.

Durable and long-lasting, stable performance: It combines the excellent rust-proof properties of austenitic stainless steel, enabling long-term use in humid, chemical, coastal and other corrosive environments without rusting. No frequent replacements are required, significantly reducing the later maintenance costs.

Full-process quality control, traceable quality: From the spectral detection of raw materials entering the factory, to the performance testing of solid solution heat treatment, and then to the mechanical performance testing, salt spray test, and intergranular corrosion test at the time of product delivery, the entire process adheres to the ISO 9001 quality management system. Each batch of products has consistent performance and is traceable, ensuring a reliable purchase and a peaceful use.

Automotive and Power Sector: Fastening of high-temperature components for automotive engines, turbochargers, exhaust systems, and racing car modifications, suitable for high-frequency vibration and high-temperature conditions

Chemical and Energy Sector: Fastening of chemical reaction vessels, boilers, heat exchangers, nuclear power equipment, and high-temperature pipelines, suitable for medium-high temperature and highly corrosive conditions

Aerospace Sector: High-temperature fastening for aircraft engines, spacecraft components, and aviation equipment, suitable for high loads, high temperatures, and corrosive environments

Industrial Furnaces and Heat Treatment Sector: Structural fastening of industrial furnaces, heat treatment equipment, and kilns, suitable for long-term medium-high temperature working conditions

Maritime and Ocean Engineering Sector: Fastening of high-temperature equipment for ships and coastal chemical facilities, suitable for humid, high salt spray, and high-temperature environments

Food and Medical High-Temperature Equipment Sector: Fastening of high-temperature sterilization equipment and food baking equipment, in line with hygiene-level usage standards