To solve this challenge, the industry developed the Bimetal Self Drilling screw — an advanced fastening solution combining the advantages of two different metals into one high-performance product.

Today, bimetal screws are widely used in roofing, cladding, steel construction, and harsh outdoor environments where durability and performance are equally important.

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WHAT IS A BIMETAL SELF DRILLING SCREW?

A Bimetal Self Drilling Screw is manufactured by combining:

• A stainless steel body
• A hardened carbon steel drill point

This unique structure allows the screw to achieve two critical functions simultaneously:

STAINLESS STEEL BODY

Provides:

• Excellent corrosion resistance
• Long service life
• Superior weather resistance
• Clean surface appearance

HARDENED CARBON STEEL DRILL POINT

Provides:

• High drilling strength
• Efficient penetration into steel substrates
• Faster installation performance
• Improved torque capability

The result is a screw capable of drilling through steel while maintaining long-term corrosion protection.

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WHY BIMETAL TECHNOLOGY MATTERS

In many outdoor construction projects, fasteners are exposed to:

• Rainwater
• Humidity
• UV radiation
• Temperature changes
• Industrial pollution
• Coastal salt environments

Standard carbon steel screws may corrode quickly under these conditions.

Meanwhile, fully stainless steel drilling screws may struggle with drilling efficiency in thicker steel because stainless steel cannot achieve the same hardness as hardened carbon steel.

Bimetal technology combines the strengths of both materials, creating a more balanced fastening solution.

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MAIN PRODUCT FEATURES

Bimetal self drilling screws offer several important advantages:

• Excellent corrosion resistance
• Strong self drilling capability
• Suitable for heavy steel applications
• Reduced risk of red rust
• Long outdoor service life
• Reliable fastening performance

These features make them increasingly popular in high-performance construction systems.

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COMMON MATERIAL COMBINATIONS

The most common bimetal screw configuration includes:

• SS304 stainless steel body + carbon steel drill point

For more demanding environments, higher corrosion-resistant grades may also be available:

• SS316 stainless steel body
• Customized coating systems on drill point area

Material selection depends on project location and environmental exposure.

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COMMON SIZES & SPECIFICATIONS

Bimetal self drilling screws are available in a wide range of standard dimensions:

DIAMETERS

• #8
• #10
• #12
• #14

LENGTHS

• 19 mm – 300 mm

HEAD TYPES

• Hex Washer Head
• Countersunk Head
• Pan Head

DRIVE TYPES

• Hex Drive
• Phillips Drive

Custom specifications can be produced according to customer requirements.

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SURFACE TREATMENT OPTIONS

Although the stainless steel body naturally provides corrosion resistance, the drill point may receive additional treatment for enhanced durability.

Available options include:

• Passivation treatment
• Anti-corrosion coating on drill point
• Specialized outdoor protection systems

These treatments help improve overall product performance in severe environments.

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TYPICAL APPLICATIONS

Bimetal screws are widely used in applications requiring both drilling strength and corrosion protection.

Typical applications include:

• Metal roofing systems
• Steel structure construction
• Sandwich panel installation
• Solar mounting systems
• Coastal construction projects
• Industrial buildings
• Outdoor architectural cladding

They are particularly suitable for projects where ordinary carbon steel screws may fail prematurely.

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APPLICATION ADVANTAGES

Compared with conventional fasteners, bimetal screws provide:

LONGER SERVICE LIFE

Better resistance to corrosion and environmental exposure.

HIGHER INSTALLATION EFFICIENCY

Strong drill point allows fast penetration into steel.

LOWER MAINTENANCE COST

Reduced risk of corrosion-related failure and replacement.

IMPROVED PROJECT RELIABILITY

Suitable for demanding outdoor and structural applications.

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RECOMMENDED INSTALLATION PRACTICES

To maximize performance, proper installation is essential.

Recommended practices include:

• Use suitable installation speed and torque
• Avoid excessive pressure during drilling
• Select correct drill point type based on steel thickness
• Ensure proper sealing washer compression
• Use compatible materials to reduce galvanic corrosion risk

Correct installation helps ensure long-term fastening reliability.

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HOW TO CHOOSE THE RIGHT BIMETAL SCREW

Before selecting a bimetal screw, consider:

ENVIRONMENTAL CONDITIONS

• Inland or coastal?
• High humidity or industrial exposure?

SUBSTRATE THICKNESS

• Light gauge steel or heavy structural steel?

REQUIRED SERVICE LIFE

• Standard commercial project or long-life infrastructure?

Choosing the proper specification ensures optimal performance and cost efficiency.

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WHY CHOOSE DD FASTENERS?

DD Fasteners specializes in high-performance fastening systems for global construction markets.

Our advantages include:

• Professional self drilling screw manufacturing experience
• Advanced bimetal production capability
• Strict quality inspection standards
• Reliable anti-corrosion solutions
• OEM and customized production support

We provide fastening solutions designed for real-world environmental and structural demands.

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CONTACT US FOR MORE INFORMATION

To learn more about Bimetal Self Drilling Screws and high-performance fastening solutions, please contact us:

Website:
www.ddfasteners.com

E-mail:
dd@ddfasteners.com

WhatsApp:
+852 68409292

Our professional sales team is ready to provide technical recommendations, samples, and the latest product information for your projects.