Cold-formed Screw Manufacturing Process – English Version (Refined & Original):
In general, screw production follows a structured sequence of processes. Additional steps may be incorporated based on product specifications and customer requirements to ensure performance and quality standards are met.
Before production begins, it's essential to confirm key product details with the customer: whether it is a standard or custom part, required tolerances, processing methods, mechanical properties, surface treatment, and packaging specifications.
- Material Preparation:
Appropriate raw materials (e.g., carbon steel, alloy steel, stainless steel, boron steel) are selected based on the application. Heat treatment is later applied to achieve the necessary mechanical properties such as strength and hardness. - Heading:
The screw head is formed using forming machines and toolings. This step is critical for dimensional accuracy and forming efficiency. - Thread Rolling:
Threads are produced by rolling dies, which enhances thread strength and consistency. - Secondary Operations (Optional, Based on Product Needs):
Depending on specific design features, additional machining processes may be required—such as turning, grooving, milling, hole drilling, or thread tapping—to meet functional or assembly requirements. - Heat Treatment:
Processes like quenching, tempering, or case hardening are applied to achieve the required mechanical strength. Standards such as ISO 898-1 or SAE J429 are followed, or customized specifications as requested by the customer. - Surface Treatment:
To improve corrosion resistance and meet functional requirements, coatings such as zinc plating or phosphate treatment are applied. Coating thickness is controlled according to customer or industry standards. - Optical Sorting (If Required):
For high-precision applications, optical sorting can be used to ensure low defect rates (e.g., ≤50ppm or ≤25ppm), based on customer quality expectations. - Final Inspection & Packaging:
Dimensional checks, hardness tests, and visual inspections are conducted. Once the parts meet specifications, they are packed according to customer requirements and prepared for shipment.
