The non-standard double-head screw (M5/M6/M8) in the 12.9-grade CNC tool turning tool bar accessories is a high-strength fastener used to fix the shim or blade. Its core functions need to take into account high strength, precise positioning, and stability, which can be specifically divided into the following key points.
1. High-strength connection and fatigue resistance
Material and grade: Grade 12.9 means that the screw is made of alloy steel and is quenched and tempered. The tensile strength is above 1220MPa, which is suitable for high-frequency vibration and high-torque scenarios in CNC machining.
Non-standard design: Customize the thread length, pitch, or head shape according to the matching requirements of the shim and the tool bar to ensure compatibility with special-shaped holes or narrow spaces.
2. Precision positioning and anti-loosening
Double-head thread structure: One end fixes the shim, and the other end connects the tool bar. The assembly gap is eliminated through the precise matching of the threads at both ends to avoid micro-displacement caused by cutting force.
Surface treatment: Some models add nickel plating or blackening process to reduce the friction coefficient and improve locking consistency.
3. Dynamic stability guarantee
Anti-shear design: thickened screw or local knurling treatment to resist radial force during turning and prevent screw deformation and fracture.
Temperature adaptability: 12.9 grade material still maintains strength at high temperature, suitable for local temperature rise environment generated by high-speed processing.
4. Maintenance and adaptability
Non-standard flexible configuration: for non-standard interfaces of different brands of tool bars, fine thread options such as M5/M6/M8 are provided, and standard tool pads such as ISO and DIN are compatible.
Removability: high hardness hexagonal or plum blossom design, easy to repeatedly disassemble and maintain without slipping.
5. Life and maintenance convenience
Wear resistance: hardness HRC39-44, 3-5 times longer life than ordinary 8.8 grade screws, reducing replacement frequency.
Convenient disassembly and assembly: standardized drive interface is compatible with general tools and simplifies maintenance process.
Typical application scenarios
Turning center: used for connecting non-standard tool bars and blades, such as diamond blades and grooving knives.
Heavy-duty machining: Reliable fastening for high feed (F≥0.3mm/r) or difficult-to-cut materials.
Selection considerations
Load calculation: The screw specifications need to be selected according to the cutting force. M8 is often used for tool bars ≥10mm.
Torque control: The installation torque must be controlled by the standard to avoid over-tightening and thread slippage.
Through the above design, non-standard double-head screws achieve a balance of high strength, high adaptability, and long life in CNC machining, and are key functional parts to ensure machining accuracy and efficiency.
