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Machine screws are precision threaded fasteners designed for use with tapped holes or nuts in machinery, electronic devices, and precision equipment. They are manufactured to tighter dimensional tolerances than standard bolts, with uniform thread profile and consistent head geometry. Available in a wide range of head styles including pan, flat, round, truss, and oval, machine screws accommodate diverse assembly requirements from flush-mount applications to high-clamp-force connections.
Zhejiang Chance & Union supplies machine screws in carbon steel, stainless steel, and alloy steel, with property classes 4.8, 8.8, and 10.9. We offer multiple finishes including zinc plating, passivation, and plain, with diameters from M2 to M20 and inch equivalents. Our thread rolling and heading processes ensure consistent quality across both standard and custom orders.
Head Style Options
- Pan Head: Standard, wider bearing surface
- Flat Head: Countersunk for flush mounting
- Round Head: Domed, decorative finish
- Truss Head: Extra-wide, low-profile
- Oval Head: Countersunk with rounded top
Product Specifications
| Parameter | Range / Options |
| Diameter range | M2 – M20 · 0-80 UNC – 3/4″ |
| Length range | 3 mm – 150 mm · custom lengths |
| Thread class | 6g (metric) · 2A (UNC) · rolled threads |
| Property classes | 4.8 · 8.8 · 10.9 · stainless A2/A4 |
| Materials | Carbon steel · alloy steel · stainless 304/316 · brass |
| Head styles | Pan · flat · round · truss · oval |
| Finish options | Zinc plated · passivated · plain · phosphate |
Production Capacity
30k
m² Facility
80+
Cold Headers
800t
Monthly Output
2k
Tons Stock
B2B Procurement Advantages
Supply Chain Stability
- Permanent stock of 5,000+ specifications across all head styles
- Storage capacity exceeding 2,000 tons ensures continuous availability
- 24-hour order processing with 3-day shipping for standard items
- Custom order lead time: 7–25 days, supporting production planning
- 80+ cold heading units provide production flexibility and redundancy
Quality Assurance
- ISO 9001 and IATF 16949 certified quality systems
- 100% optical sorting for dimensional accuracy
- Full traceability with material test reports (MTR) and heat numbers
- 72-hour salt spray testing per ASTM B117 for coating validation
- Ex-factory pass rate: 99.9%
Engineering & Custom Support
With nearly 20 years of industry experience, our R&D team has developed over 1,000 custom fastener solutions for clients across 25 countries. We invest 5% of annual revenue into R&D, focusing on:
- Precision thread design: Custom thread lengths, pitch variations, and modified profiles for specific engagement requirements
- Head geometry optimization: Non-standard head diameters, heights, and drive types (Phillips, Pozidriv, Torx, hex socket)
- Material selection: Guidance on carbon steel, stainless, brass, or alloy steel based on strength, corrosion, and conductivity needs
- Prototyping: Rapid sample production for fit and function validation before volume production
Application Scenarios
- Electronics: PCB mounting, enclosure assembly, and component securing
- Automotive: Interior trim, control modules, and sensor mounting
- Medical devices: Precision instrument assembly and equipment frames
- Industrial control: Panel mounting, terminal blocks, and junction boxes
- Consumer appliances: Small appliance assembly and component fastening
Selection Guide for Procurement
When sourcing machine screws for production, consider these factors that impact assembly efficiency and total cost:
- Head style: Pan head for general use; flat head for flush-mount applications; truss head for soft materials; oval head for decorative finishes.
- Drive type: Phillips for standard applications; Pozidriv for higher torque; Torx for tamper-resistant or high-torque assemblies; hex socket for compact access.
- Thread fit: Class 6g/2A for standard clearance; tighter fits available for precision assemblies where thread engagement is critical.
- Material and coating: Stainless steel for corrosion resistance; zinc-plated carbon steel for cost-effective indoor applications; passivated for medical or food contact.
- Length tolerance: Standard lengths per DIN/ISO; custom lengths for specific stack-up requirements.
Frequently Asked Questions
What is the difference between a machine screw and a standard bolt?
Machine screws are precision fasteners with uniform threading along the entire shank, designed for use with tapped holes or nuts in machinery and equipment. They are available in smaller diameters (typically under 1/2 inch or M12) and tighter tolerances than standard bolts. Bolts are generally larger and used with nuts in structural connections.
What head styles and drive types are available?
We offer pan, flat, round, truss, and oval head styles. Drive types include Phillips, Pozidriv, Torx (internal and external), hex socket, and slotted. Custom drive combinations are available for volume orders.
How do you ensure consistent thread quality?
All machine screws feature rolled threads for improved fatigue resistance and dimensional consistency. We use thread-rolling dies maintained to strict tolerances, with regular gauge verification. Each batch undergoes go/no-go gauge inspection and optical sorting for thread profile verification.
What is your typical lead time for machine screws?
Standard sizes in stock can ship within 3 days. For custom head styles, lengths, or materials, lead time is typically 7 to 25 days depending on order quantity and specification complexity. We support both small-batch prototyping and large-volume production orders.
Can you produce machine screws to non-standard specifications?
Yes. Our R&D team has developed over 1,000 custom fastener solutions. We can accommodate non-standard head dimensions, thread configurations, drive types, and special material or coating requirements. We provide engineering consultation to optimize fastener design for your specific assembly process.
