Description and Translation of GB/T 2670.1 Fasteners
GB/T 2670.1 fasteners, a key Chinese standard for mechanical components, function as countersunk flat head rivets widely used in machinery, electrical equipment, and sheet metal assemblies. Their primary role is to create permanent non-threaded connections, joining thin-walled components by forming a secure head through riveting, ensuring flush surface finish and reliable load transmission in applications requiring minimal protrusion.
In terms of materials, GB/T 2670.1 fasteners are predominantly manufactured from aluminum alloys (e.g., 5052, 6061) for lightweight applications, and carbon steel (e.g., Q235) for higher strength requirements. Copper and copper alloys are specified for electrical conductivity needs, while stainless steel (e.g., 304) variants provide corrosion resistance in harsh environments.
Surface treatments include anodizing for aluminum rivets to enhance corrosion resistance and wear performance, zinc plating for carbon steel variants to prevent rust, and passivation for stainless steel to maintain its anti-corrosive properties. These treatments optimize durability while ensuring compatibility with various operating conditions.
Key characteristics of GB/T 2670.1 fasteners include countersunk head designs for flush mounting, precise shank diameters, and controlled dimensional tolerances ensuring assembly accuracy. Their mechanical attributes feature appropriate shear strength (varies by material), good ductility for forming during riveting, and uniform head geometry. Additionally, they exhibit reliable permanent fastening performance and excellent vibration resistance, making them indispensable in sheet metal fabrication and mechanical assembly.
| Thread Size | ST2.9 | ST3.5 | ST4.2 | ST4.8 | ST5.5 | ST6.3 | ||||
| P | Pitch | 1.1 | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 | |||
| a | 1.1 | 1.3 | 1.4 | 1.6 | 1.8 | 1.8 | ||||
| da | max | 3.5 | 4.1 | 4.9 | 5.6 | 6.3 | 7.3 | |||
| dk | max=nominal size | 5.6 | 7 | 8 | 9.5 | 11 | 12 | |||
| min | 5.3 | 6.64 | 7.64 | 9.14 | 10.57 | 11.57 | ||||
| k | max=nominal size | 2.4 | 2.6 | 3.1 | 3.7 | 4 | 4.6 | |||
| min | 2.15 | 2.35 | 2.8 | 3.4 | 3.7 | 4.3 | ||||
| r | min | 0.1 | 0.1 | 0.2 | 0.2 | 0.25 | 0.25 | |||
| R | ≈ | 5 | 6 | 6.5 | 8 | 9 | 10 | |||
| y | Ref. | Type C | 2.6 | 3.2 | 3.7 | 4.3 | 5 | 6 | ||
| Type F | 2.1 | 2.5 | 2.8 | 3.2 | 3.6 | 3.6 | ||||
| Type R | / | 2.7 | 3.2 | 3.6 | 4.3 | 5 | ||||
| Socket No. | 10 | 15 | 20 | 25 | 25 | 30 | ||||
| A | Ref. | 2.8 | 3.35 | 3.95 | 4.5 | 4.5 | 5.6 | |||
| t | max | 1.27 | 1.4 | 1.8 | 2.03 | 2.03 | 2.42 | |||
| min | 1.01 | 1.14 | 1.42 | 1.65 | 1.65 | 2.02 | ||||
Tapping screws sourced with the specified thread form, point, head, drive, material and finish.
Sheet-metal, plastics or prepared-hole assemblies when the screw design is validated for the receiving material.
Suitability must be approved against the customer drawing, joint design and service conditions. Product-specific numbers are not published until confirmed by Shuojia and the selected manufacturing partner.
Drawing- and sample-based requests are reviewed with qualified manufacturing partners. State any required material certificate, dimensional report, thread-gauge result, hardness record, coating-thickness report or third-party inspection before quotation.
State the complete standard designation and revision for the Tapping Screw, or attach a controlled drawing. Similar product names do not guarantee dimensional interchangeability.
Specify the required material, property class or grade for the Tapping Screw. The proposed supply is confirmed against those requirements before quotation.
Confirm thread form, point, diameter, length, head, drive, pilot hole, material and coating. Add any tolerances or mating-part details that control fit or function.
State the service environment, coating system, colour, thickness and corrosion-test requirement. Shuojia will confirm the available Tapping Screw sourcing route against the RFQ.
Request the exact records needed, such as material certificates, dimensional results, thread-gauge checks, hardness results or coating-thickness reports. Availability is confirmed in the quotation.
They depend on the final Tapping Screw specification, quantity, tooling, finish, inspection and packing. The written quotation confirms all three before an order is placed.
Send the standard or drawing, material and grade, dimensions, finish, quantity, packing, documentation, destination and required delivery date for the Tapping Screw.
