Standard fasteners do not fit every application. Custom fasteners are engineered to meet specific requirements for size, material, strength, or coating. Here is the complete process from your drawing to final delivery.
Step 1: Design Review
Our engineering team reviews your drawing or specifications:
- Dimensional requirements (diameter, length, head type)
- Material specification (grade, alloy, treatment)
- Quantity and delivery timeline
- Application environment and performance requirements
- Applicable standards (DIN, ISO, ANSI, or custom)
Step 2: Material Selection
Based on your application, we recommend the optimal material:
- Carbon steel for general purpose
- Stainless steel for corrosion resistance
- Alloy steel for high strength or temperature
- Exotic alloys (Inconel, Hastelloy, Monel) for extreme conditions
Step 3: Tooling and Setup
Custom fasteners require dedicated tooling:
- Header dies for forming heads
- Thread rolling dies
- Special cutters for unique profiles
- Fixture tools for secondary operations
Tooling lead time: 7-15 days depending on complexity.
Step 4: Production Methods
Cold Heading (Upset Forging)
For volumes over 1,000 pieces. Wire is cut and formed at high speed. Excellent material utilization and grain flow for superior strength.
CNC Machining
For prototypes and small batches. Bar stock is machined to exact dimensions. Higher cost per piece but no tooling investment.
Hot Forging
For large diameters (M24+) or complex shapes. Steel is heated and forged. Used for anchor bolts, special heads, and heavy structural fasteners.
Step 5: Thread Processing
- Thread rolling: Cold-formed threads, superior fatigue life
- Thread cutting: For special profiles or low volumes
- Thread grinding: For precision applications (gauge, aerospace)
Step 6: Heat Treatment
High-strength fasteners (Grade 8.8+) require heat treatment:
- Quenching in oil or polymer
- Tempering to achieve target hardness
- Testing to verify mechanical properties
Step 7: Surface Treatment
Applied per your specification:
- Zinc plating (electroplated)
- Hot-dip galvanizing
- Dacromet/Geomet coating
- Passivation (stainless steel)
- Black oxide or phosphate
Step 8: Quality Control
Every batch undergoes:
- Dimensional inspection (first article and sampling)
- Hardness testing
- Coating thickness measurement
- Visual inspection for defects
- Thread gauge verification
Step 9: Packaging and Shipping
- Standard packaging: bulk cartons with poly bags
- Custom packaging: blister packs, labeled boxes, kits
- Full documentation: material certs, inspection reports, packing list
- Global shipping by sea, air, or express
Lead Times
- Simple custom fasteners: 15-20 days
- Complex or large diameter: 25-35 days
- Exotic materials: 30-45 days
- Rush orders available with surcharge
Chaoshuo Trading – Custom fastener manufacturing since 2010. Send us your drawing for a free quote within 24 hours.