Single-Start Thread Design for Easier Control of Driving Depth
FAST-TT uses a single-start thread design, meaning the screw advances by one thread pitch per revolution. Compared with multi-start threads, its axial advance is slower, making it suitable for assembly operations where driving depth, stopping position, and torque control are important.
Triangular Thread Profile Helps Reduce Thread-Forming Resistance
The triangular or trilobular thread profile does not contact the entire hole wall at the same time. Instead, the raised portions of the thread progressively displace the material, helping reduce contact resistance during thread forming and allowing smoother installation.
Actual thread-forming torque will still depend on workpiece material, hardness, pilot hole size, thread diameter, and surface treatment.
Forms Internal Threads Directly in a Pilot Hole
When driven into a properly sized pilot hole, the screw uses its thread profile to displace the material and form internal threads that mate with the screw, reducing the need for a separate tapping operation.
FAST-TT screws generally still require a suitable pilot hole and are not intended to drill directly into every metal material.
Helps Reduce Metal Chip Generation
FAST-TT primarily forms internal threads through plastic deformation of the material. Compared with self-tapping screws with cutting edges or cutting slots, this helps reduce the amount of metal chips generated during fastening.
This makes FAST-TT suitable for electronic equipment, mechanical components, metal housings, and other products where internal cleanliness is important.
Improves Thread Contact Stability
Because the internal threads are formed directly by the screw, the resulting thread surfaces can closely match the screw profile, helping improve thread engagement and fastening stability.
Actual pull-out strength and load capacity should still be verified according to workpiece material, wall thickness, pilot hole size, and effective thread engagement.
Provides Auxiliary Anti-Loosening Performance
The special triangular thread profile can increase localized contact pressure and friction between the screw and the formed internal threads. Under general vibration conditions, this may help reduce the possibility of self-loosening.
The triangular-thread design should be regarded as an auxiliary anti-loosening feature. Additional locking methods should still be considered for high-vibration or safety-critical applications.
May Eliminate the Need for a Separate Nut
FAST-TT screws can be driven directly into workpieces with suitable pilot holes. In one-sided assembly applications or locations where rear-side nut installation is difficult, this can reduce the need for nuts and other fastening components.
Simplifies Tapping and Assembly Processes
Once the pilot hole is prepared, the screw can form the internal thread and fasten the component in a single operation. This helps reduce separate tapping, nut installation, and multi-component assembly steps, shortening the overall production process.
Suitable for Sheet Metal and Die-Cast Components
Depending on thread diameter, thread pitch, pilot hole size, and engagement depth, FAST-TT screws can be used with steel sheet, aluminum alloys, zinc alloys, and die-cast components. They are especially useful for structures where pre-tapping is inconvenient or rear-side access is limited.
Suitable for Automated Fastening
FAST-TT screws with consistent dimensions and thread profiles can be used with vibratory bowls, feeding tracks, and automatic screw-fastening equipment, making them suitable for high-volume production and assembly lines with demanding cycle-time requirements.
For automated fastening, rotational speed, downward force, thread-forming torque, final tightening torque, and stopping position should be properly controlled.
Multiple Head Types and Surface Treatments Available
Different head types, drive styles, screw materials, heat treatments, and surface finishes can be selected according to product appearance, installation tools, operating environment, and corrosion-resistance requirements.
Customization Based on Drawings and Samples
FAST-TT screws can be customized according to customer engineering drawings or physical samples, including screw head type, drive style, thread diameter, thread pitch, length, triangular-thread profile, point configuration, material, hardness, tolerances, heat treatment, and surface treatment.
Common Applications
FAST-TT screws are commonly used in:
- Metal enclosures, cabinets, and sheet metal structures
- Electronic and electrical equipment
- Automotive and motorcycle components
- Aluminum alloy and zinc alloy die-cast parts
- Home appliances and consumer products
- Telecommunications and information equipment
- Motors, fans, and mechanical components
- Instruments and precision equipment
- Metal furniture and hardware accessories
- One-sided assembly locations or areas where rear-side nut installation is difficult
- Mass-production and automated fastening lines
Key Considerations When Selecting FAST-TT
Before selection, confirm the workpiece material, hardness, sheet thickness, pilot hole size, effective thread engagement length, and expected load. The workpiece must have sufficient plasticity and ductility to form complete and stable internal threads during the thread-forming process.
If the pilot hole is too small, driving and thread-forming torque may become excessively high, potentially causing screw breakage, drive recess damage, workpiece cracking, or excessive load on fastening equipment. If the pilot hole is too large, thread engagement may be insufficient, resulting in free spinning, thread stripping, or reduced pull-out strength.
The screw surface hardness must be sufficient to displace the workpiece material and form the internal thread, while the core should retain adequate toughness. Improper hardness, heat treatment, or material selection may result in thread wear or brittle screw fracture during fastening.
Fastening tools should be set to appropriate rotational speed, downward force, and shut-off torque. The torque required during the thread-forming stage differs from the final clamping torque after the screw head seats against the workpiece, so actual fastening tests should be conducted before mass production.
If repeated disassembly is required, the durability of the formed internal threads should be confirmed. Repeated removal may cause wear or deformation of the workpiece threads and reduce subsequent driving torque. For products requiring frequent maintenance, pre-tapped holes, insert nuts, or other reusable fastening structures may be more suitable.
For outdoor, humid, corrosive, high-vibration, or high-load environments, screw material, surface treatment, anti-loosening methods, and the risk of galvanic corrosion between dissimilar metals should also be evaluated.
