Corrosion-Resistant Hexagon Socket Screws for Industrial Use

Length ————— Model	10mm-30mm	30mm-50mm	50mm-80mm	80mm-100mm	100mm-150mm
1/4-20	●	●	●
5/16-18	●	●	●
Silicon bronze internal hex bolts are high-end precision fasteners specifically developed for complex and harsh industrial conditions. Made from premium silicon bronze alloy, they are crafted using mature metal forging and precision machining processes. Featuring a classic internal hex countersunk hole design with high-precision standard threads, these bolts overcome the performance limitations of traditional carbon steel, brass, and ordinary stainless steel fasteners, integrating multiple characteristics such as corrosion resistance, anti-seize, high toughness, easy assembly and disassembly, and electrical conductivity. The finished product undergoes multiple meticulous finishing processes, resulting in a burr-free, flash-free, structurally deformable, and internally crack-free finish. With high dimensional accuracy and strong adaptability, they are perfectly suited for various special assembly scenarios, including precision machinery, corrosive environments, coastal outdoor applications, and electrical equipment, making them the preferred accessory for upgrading industrial equipment fasteners.3/8-16	●	●	●	●	●
1/2-13	●	●	●	●	●
9/16-12	●	●	●	●	●
5/8-11	●	●	●	●	●
3/4-10	●	●	●	●	●
M3-0.5	●	●
M4-0.7	●	●	●	●	●
M5-0.8	●	●	●
M6-1.0	●	●	●
M8-1.25	●	●	●	●
M10-1.5	●	●	●	●
M12-1.75	●	●	●	●
M16-2.0	●	●	●	●	●
M20-2.5	●	●	●	●	●

Product Specifications

Silicon bronze internal hex bolts are high-end precision fasteners specifically developed for complex and harsh industrial conditions. Made from premium silicon bronze alloy, they are crafted using mature metal forging and precision machining processes. Featuring a classic internal hex countersunk hole design with high-precision standard threads, these bolts overcome the performance limitations of traditional carbon steel, brass, and ordinary stainless steel fasteners, integrating multiple characteristics such as corrosion resistance, anti-seize, high toughness, easy assembly and disassembly, and electrical conductivity. The finished product undergoes multiple meticulous finishing processes, resulting in a burr-free, flash-free, structurally deformable, and internally crack-free finish. With high dimensional accuracy and strong adaptability, they are perfectly suited for various special assembly scenarios, including precision machinery, corrosive environments, coastal outdoor applications, and electrical equipment, making them the preferred accessory for upgrading industrial equipment fasteners.

Core Product Features

1. High-quality alloy base material for stable and durable performance: Utilizing industrial-grade C65100 and 

C65500 silicon bronze alloys, with a scientifically proportioned ratio of silicon, manganese, and other alloying 

elements, the metal structure is dense and uniform, free from defects such as porosity, slag inclusions, and 

looseness. This avoids problems like breakage, corrosion, and failure from the source, ensuring stable 

performance without degradation over long-term use.

2. Fully precision-machined for high assembly fit: Employing an integrated hot forging process for shaping, 

combined with automated processes such as CNC precision turning, fully automatic thread rolling, and 

precision hole finishing, the internal hexagonal holes are standard and regular, ensuring even and 

balanced stress distribution and a high degree of fit for assembly and disassembly tools. The thread profile is 

full and regular, with uniform pitch and small engagement clearance, eliminating stripping and disengagement, 

and is compatible with various standard fasteners.

3. Ultra-low friction characteristics, preventing thread seizing: Unlike conventional stainless steel fasteners 

that are prone to seizing and tearing, silicon bronze material inherently possesses low friction properties, 

eliminating the need for additional lubrication. It remains smooth and fluid even after repeated assembly 

and disassembly, effectively adapting to equipment assembly scenarios requiring frequent maintenance 

and disassembly.

4. Combines electrical and thermal conductivity, suitable for electrical applications: Inheriting the 

excellent electrical and thermal conductivity of copper alloys, it boasts low resistivity and rapid heat dissipation. 

While securing equipment, it achieves safe conductivity and rapid heat dissipation, 

fulfilling both mechanical fixing and electrical connection needs in one unit.

5. High temperature resistance and oxidation resistance, wide adaptability to various operating 

conditions: The alloy material exhibits excellent high-temperature resistance, preventing softening, 

deformation, peeling, and oxidation under medium- and high-temperature industrial conditions.

 It can stably adapt to special operating environments such as thermal equipment and 

high-temperature processing machinery.

6. Original appearance, weather-resistant, long-lasting, beautiful and durable: The 

product adopts original fine grinding surface treatment, without electroplating, 

spraying or other post-coatings. The surface is smooth and clean, with strong anti-oxidation 

and anti-fouling ability. It is not easy to discolor or age when used in the long-term outdoor 

and humid environment. The overall assembly looks neat and tidy.

Parameter	Value
Material	silicon bronze
Size Range	M3 - M24 (with lengths from 6mm to 200mm)
Drive Type	Hexagon socket (internal) with depth optimized for high torque transmission
Thread Standard	ISO metric (6g class fit) with full thread or partial thread options
Corrosion Resistance	10,000+ hours salt spray resistance (per ASTM B117 testing)

Key Product Advantages

1. Strong Weather and Corrosion Resistance, Adaptable to Extreme Conditions: Demonstrates 

exceptional resistance to harsh environments such as salt spray, seawater immersion, 

acid and alkali corrosion, and dampness/mildew. Compared to ordinary carbon steel 

and brass fasteners, its corrosion resistance, rust resistance, and fracture resistance 

are significantly improved, resulting in an actual service life 3-5 times longer, 

drastically reducing the frequency of equipment parts replacement.

2. Balanced Mechanical Properties, Safe and Reliable Fastening:The product features 

a reasonable ratio of toughness to tensile strength, exhibiting excellent impact, tensile, 

and compressive strength. It is not easily deformed, loosened, or broken under high pressure, 

high load, and dynamic vibration conditions, ensuring long-lasting and stable locking capacity 

and comprehensively guaranteeing the safety and stability of the overall equipment assembly structure.

3. Lower Maintenance Costs, Suitable for High-Frequency Maintenance: With its superior anti-seize 

and wear-resistant properties, subsequent equipment maintenance, disassembly, 

and replacement operations are simple and efficient, requiring no special tools or auxiliary consumables. 

This effectively saves on labor maintenance costs and parts wear costs, 

making it suitable for industrial-scale batch maintenance scenarios.

4. Versatile and Highly Replaceable: Breaking away from the limitations of traditional fastener applications, 

it is compatible with diverse needs such as mechanical fastening, electrical conductivity, 

outdoor corrosion protection, and marine salt resistance. Its versatility far surpasses

 that of ordinary fasteners, allowing for a one-stop replacement of multiple conventional accessories

 and simplifying procurement.

5. Higher Safety Factor and Adaptability to Special Working Conditions: The material is non-magnetic, 

unlikely to generate electrical sparks, and has stable physical and chemical properties. It is non-toxic, 

harmless, safe, and environmentally friendly, making it safe for use in flammable and explosive environments, 

precision instruments, high-risk chemical environments, and other special working scenarios, 

mitigating the risk of safety accidents.

Features

• Concealed head design that creates smooth surfaces, reducing contamination risks and improving safety in food and pharmaceutical environments

• Superior resistance to acids, alkalis, and industrial chemicals, maintaining integrity in aggressive cleaning regimes

• High torque transmission through precision-machined hexagon socket drive, minimizing cam-out during installation

• Available with adhesive patch (thread-locking compound) for vibration resistance in dynamic applications

• Passivated surface finish that enhances natural oxide layer for additional corrosion protection

Wide range of applications

Ideal for chemical processing equipment (reactors, pipelines), food processing machinery (mixers, conveyors), pharmaceutical production lines (sterilization equipment), and marine industrial systems (offshore platforms, shipboard machinery) requiring frequent cleaning and sanitization. Suitable for cleanroom environments and applications with strict hygiene standards.

This silicon bronze internal hex bolt boasts versatile performance, 

making it suitable for precision fastening operations across multiple industries and working conditions. 

Its core applications cover major industrial sectors:

1. Marine and Coastal Engineering: Widely used in ship hull assembly, deck hardware fixing, 

offshore wind power platforms, dock piers, seawater pipelines, dock infrastructure, 

and other coastal equipment subject to prolonged exposure to seawater and salt spray.

2. Chemical and Environmental Protection Equipment: Suitable for assembling industrial 

equipment subject to prolonged exposure to corrosive media, such as chemical reactors, 

acid and alkali fluid transportation equipment, industrial corrosion-resistant storage tanks, 

wastewater treatment systems, and exhaust gas purification devices.

3. Power and New Energy Industry: Can be used for structural fixing and 

conductive connection assembly of high and low voltage switchgear, electrical terminals, 

complete sets of power equipment, new energy storage equipment, and precision electrical instruments.

4. Outdoor Infrastructure and Curtain Wall Engineering: Suitable for outdoor steel structure frames,

 building curtain wall decoration, landscape engineering, ancient building restoration, 

coastal outdoor machinery, and other infrastructure projects requiring long-term stable fastening.

5. Precision Machinery and Instrument Manufacturing: Suitable for high-end precision machine tools, 

hydraulic transmission equipment, automated instruments and meters, 

and light industrial precision machinery, where extremely high assembly precision and wear control are required.

6. Special Industrial Support: Meets the safety and fastening needs of high-end special fields such 

as aerospace components, military equipment, high-temperature machinery, 

and explosion-proof industrial equipment.

Packaging and Logistics Transportation

1. Refined Protective Packaging: Products are individually sealed in sealed bags 

and enclosed in thickened cardboard boxes to prevent moisture and oxidation; 

waterproof and moisture-proof stretch film is used for wrapping, 

and solid wooden pallets are used for secure packaging, with layered and categorized placement.

2. Diverse Logistics and Distribution: Supports multiple delivery methods including dedicated land transport, 

air freight, and express delivery. Urgent orders can be prioritized and expedited. 

Full logistics information is traceable.

3. Comprehensive After-Sales Guarantee:All products undergo a 

double quality inspection process before leaving the warehouse, 

strictly screening out defective and flawed products.

Real customer testimonials

1. A coastal engineering client: "We've been purchasing these silicon bronze hexagon socket head cap bolts 

in bulk for a long time, specifically for securing equipment at seaside docks. 

The salt spray corrosion environment is extremely harsh, 

but these bolts have excellent rust and corrosion resistance. After three years of use, 

there has been almost no corrosion or loosening. They also don't jam during disassembly or assembly, 

making them far more cost-effective than stainless steel fittings."

2. A chemical equipment manufacturer: "Our workshop is constantly exposed to acidic and alkaline media. 

Ordinary bolts are prone to corrosion and breakage, requiring frequent replacements. 

These silicon bronze bolts are suitable for corrosive conditions, offering high strength without deformation or rust, 

significantly reducing equipment failure rates. Their stable quality makes them a long-term, reliable supplier."

3. A precision electrical equipment manufacturer: "We have very high requirements for the precision 

and conductivity of fasteners. These bolts have precise threads, a tight fit without loosening, 

stable conductivity, and a flawless surface. Strict factory quality control ensures zero loss upon delivery, 

fully meeting the production and assembly standards for precision electrical equipment."

4. Outdoor infrastructure construction team: "The biggest fear in outdoor construction is the aging 

and rusting of fasteners, and frequent repairs and replacements. These silicon bronze bolts are

 resistant to aging and weathering, require virtually no maintenance after installation, 

come in a full range of specifications, and offer fast delivery for non-standard customization,

 providing an excellent overall user experience."