12.9 Grade Black Oxide Allen Head Socket Cap Screws High Strength Hexagon Socket Bolts08.jpg

12.9 Grade Black Oxide Allen Head Socket Cap Screws High Strength Hexagon Socket Bolts09.jpg

12.9 Grade Black Oxide Allen Head Socket Cap Screws High Strength Hexagon Socket Bolts10.jpg

12.9 Grade Black Oxide Allen Head Socket Cap Screws High Strength Hexagon Socket Bolts11.jpg

12.9 Grade Black Oxide Allen Head Socket Cap Screws High Strength Hexagon Socket Bolts12.jpg

High-Strength 12.9 Grade Black Oxide Allen Head Socket Cap Screws from China Suppliers & Factory

Name: 12.9 Grade Socket Cap Screw (Allen Head Bolt)
Material: SCM435/40Cr Alloy Steel
Standards: GB/T 70.1, DIN 912, ISO 4762, ANSI/ASME B18.3
Grade: 12.9 (High-strength alloy steel with a tensile strength ≥1200MPa and yield strength ≥1080MPa)
Specifications: M2-M36 (customizable)
Surface Treatment: Options include blackening/oxidation for anti-oxidation, improved surface hardness, and reduced friction coefficient; nickel plating; zinc plating; and Dacromet treatment.
Design Features: Made from high-strength alloy steel, featuring a hexagonal drive structure, a cylindrical head design, precision knurled texture, and a high-precision full-thread design.
Applications: Ideal for machinery manufacturing, the automotive industry, construction machinery, industrial equipment, and precision instruments.
Delivery Time: 15-30 days after receipt of advance payment.
Origin: China
Brand: JGD
Minimum Order Quantity: 10,000 pieces, negotiable
Samples: Available
Packaging: Available in Boxed, Bulk, Pallet or customized packaging options.
OEM: Available
As a leading factory and supplier in China, we are committed to providing high-quality socket cap screws designed to meet the demands of various industries.

304 Stainless Steel Cross Recessed Countersunk Head Self-Tapping Screws01

304 Stainless Steel Cross Recessed Countersunk Head Self-Tapping Screws02

Key Features

Our self-tapping screws are crafted from food-grade 304 stainless steel and treated to achieve metric Grade 12.9 ultra-high strength, overcoming the traditional hardness limitations of standard stainless steel. Featuring a countersunk Phillips head design, these screws can be installed flush with the workpiece surface for a zero-profile finish, making them ideal for precision electronics and architectural decoration. We have optimized the thread geometry for different substrates (metal, wood) to ensure low-torque driving with high-torque clamping, effectively preventing stripping. As a superior alternative to standard Tek screws, these fasteners perform exceptionally well in thin sheet metal connections, providing an intelligent fastening solution that balances aesthetics with high load-bearing capacity.

304 Stainless Steel Cross Recessed Countersunk Head Self-Tapping Screws03

304 Stainless Steel Cross Recessed Countersunk Head Self-Tapping Screws04

Precision Manufacturing Process

From wire rod to finished product, we strictly adhere to multiple international standards including ISO, DIN, ANSI, and GB. Utilizing multi-station cold forging technology, we ensure shank diameter tolerances are controlled within microns. Threads are formed through a precision thread rolling process to enhance fastening force. For non-standard requirements, we employ optical imaging sorters to reject minute defects like head cracks. In post-treatment, we offer a wide range of surface finishing options: from conventional zinc plating and nickel plating to highly corrosion-resistant Hot-Dip Galvanizing (H.D.G.), as well as decorative polishing and black anodizing. We even provide food-grade passivation treatment, ensuring every screw has a prolonged fatigue life in demanding environments.

Transparency & Customization

As a source factory, we are committed to breaking down the information barriers of traditional trade. From mill certificates for raw materials to hardness grades (covering Grade 4.8 to Grade 12.9, as well as A2-70 and A4-80 marine-grade stainless steel), all test data is traceable. We support full-chain customization: dimensionally, we can adjust thread length and head thickness according to drawings; functionally, we can combine processes like sandblasting, electrophoretic coating (e-coating) , or chrome plating. Whether you need British Standard (BS) fasteners or require a special colored anodized finish, we offer small-batch sampling. This ensures that when you purchase fasteners from us, you not only receive high-quality products but also full transparency and control over the entire process, from material selection to packaging.

Intelligent Warehousing Services for Fasteners

No Pre-Drilling · Rust Resistant · More Secure

This stainless steel Phillips countersunk self-tapping screw, with its rust-resistant and corrosion-resistant material, one-step self-tapping design, and aesthetically pleasing countersunk head structure, has become the preferred solution for metal substrate fastening scenarios that is efficient, reliable, and aesthetically pleasing.

Product Details

Manufacturing Process

Multi Station Cold Heading Technology
Intelligent Heat Treatment System
Micron-Level Thread Rolling Process
Fully Automatic Optical Sorting
Environmentally Friendly Surface Treatment Line
Metallographic And Mechanical Joint Laboratory

Quality Control System

Raw Material Source Locking
Furnace Number Batch Full Traceability
Third Party Material Certification
Process Parameters Open And Transparent
Salt Spray Test Real Time Monitoring
International Standard Compliance Declaration

Flexible Customization Capability

Customizable head/slot Shapes
Extreme Application Of Special Materials
Breakthroughs In Extra Large/Long Specifications
Integrated Assembly Of Components
Customizable Surface Treatment Colors
Personalized Packaging And Labeling

Technical Service

On-Site Failure Analysis
Selection Calculation And BOM Optimization
Installation Tool Selection Guidance
Inventory Management (VMI) Trusteeship
Free Sample Making And Testing
International Standard Translation And Interpretation

Feature 01

Black Oxide for Rust & Corrosion Resistance

Made of SCM435/40Cr alloy steel with black oxide finishing, the surface forms a magnetic iron oxide film that effectively blocks humid air and mild corrosive media. Although not as salt-spray resistant as stainless steel, it prevents red rust in dry indoor environments, mechanical assembly, and engine compartments. The oxide layer also increases surface hardness and reduces fretting wear, with no hydrogen embrittlement risk – ideal for high-strength fastening.

Feature 02

Ultra-High Strength Metal for Anti-Loosening

Grade 12.9 offers tensile strength ≥1200MPa and yield strength ≥1080MPa, far exceeding stainless steel or Grade 8.8 bolts. When tightened, the hex socket drive transmits high torque, creating enormous clamping force and significantly increasing thread friction. Even under severe vibration, impact, or cyclic loads (e.g., construction machinery, racing chassis), the bolt remains secure. Metal material never ages, ensuring lasting locking performance.

Feature 03

Long Service Life with High Wear Resistance

The black oxide layer provides self-lubricating properties, reducing thread friction and minimizing galling or cold welding during assembly. The cylindrical head and fine knurling enable hand-tightening without tool slippage or surface damage. Proven in fatigue tests, the head-to-shank fillet and thread root withstand millions of cycles without cracking. Compared to common zinc-plated bolts, this product offers superior wear resistance, longer replacement intervals, and lower maintenance costs.

Application Scenarios

304 Stainless Steel Cross Recessed Countersunk Head Self-Tapping Screws05

High-Quality 12.9 Grade Socket Cap Screw Display

Frequently Asked Questions (FAQ)

Q What raw materials are used for Grade 12.9 socket cap screws?

Our Grade 12.9 socket cap screws are manufactured using high-grade SCM435 or 40Cr alloy steel, ensuring superior tensile and yield strength properties for heavy-duty fastening.

Q What are the primary benefits of the black oxide finish?

The black oxide process forms an anti-corrosion magnetic iron oxide film. It provides mild corrosion protection, eliminates hydrogen embrittlement risks, reduces thread friction, and provides an aesthetic, non-reflective finish.

Q How does Grade 12.9 performance compare to Grade 8.8 bolts?

Grade 12.9 offers a minimum tensile strength of 1200 MPa and yield strength of 1080 MPa, which is significantly stronger than Grade 8.8 fasteners, delivering superior clamping force and anti-loosening reliability under heavy dynamic loads.

Q Are custom head geometries, lengths, and coatings supported?

Yes, we provide flexible customization services including special head/drive types, extra-long dimensions, non-standard materials, custom surface finishes, and tailored packaging configurations.

Q What quality control and inspection procedures are implemented?

Every batch undergoes optical sorting, raw material furnace traceability, metallographic testing, thread precision verification, and real-time salt spray corrosion monitoring with third-party certification support.

Q Can I request free product samples for testing and evaluation?

Yes, we provide free sample manufacturing and testing services along with technical guidance, selection calculations, and BOM optimization to assist your engineering design requirements.