Release time：2020-01-16 18:44 Browse：
“Red forging” refers to a hot forging process where metal is heated to a red-hot state and then formed into shape. It differs from cold heading or cold forging and is typically used for larger or non-standard screws that cannot be easily formed by cold methods.
| Problem | Description |
|---|---|
| Poor dimensional accuracy | Thermal expansion and contraction make it difficult to control tolerances, affecting fit and performance. |
| Imprecise threads | Threads may be poorly formed since the metal is less stable at high temperatures. |
| Rough surface finish | Oxidation and scaling during hot forging result in rougher surfaces, even after surface treatment. |
| Unstable mechanical properties | Uneven heating and grain structure can affect the screw's strength and toughness. |
| Bending or deformation | Long screws are prone to bending due to internal stresses and uneven cooling. |
| Low production efficiency and higher cost | Hot forging is slower and more labor-intensive than cold forming. |
| Difficult heat treatment control | Irregular structure makes it harder to achieve consistent results in heat treatment. |
High accuracy is required for the head, shaft, and threads.
Surface finish needs to meet strict appearance or coating standards.
Customers expect consistency in appearance across batches.
Applications may involve structural load, requiring reliable fit and strength.
Mechanical properties such as tensile or shear strength must meet specific standards.
| Alternative Process | Advantages |
|---|---|
| Multi-station cold forging | High precision, high production efficiency, suitable for mass production. |
| Cold drawing with machining | Good for small batches or non-standard sizes needing high accuracy. |
| Warm forming with controlled heat treatment | Suitable for medium-length screws needing balanced properties. |
| Welding with CNC threading | For ultra-long screws (e.g., over 400mm), combining welding and machining ensures strength and straightness. |
Red-forged long screws are flexible for production but often fail to meet the high standards for accuracy, surface quality, and mechanical performance required in many industrial or construction applications.
