THREADING Solutions

Thread rolling is a cold-forming process that uses precision dies to plastically deform the surface of a cylindrical blank, shaping it into the desired thread profile. Unlike cutting or grinding, this method produces no chips, resulting in zero material waste and a cleaner manufacturing environment.

⚙️ Key Characteristics and Benefits

• Material Efficiency: No chips are generated, preserving the integrity of the starting material.

• Dimensional Control: The starting bar diameter must be tightly controlled to achieve accurate thread geometry and meet tolerance requirements.

• Enhanced Strength: The thread-forming action work-hardens the material, producing threads that are stronger and more fatigue-resistant than cut threads.

• Superior Finish: Threads are formed without burrs, reducing the need for secondary finishing operations.

• High Throughput: The process is fast and well-suited for high-volume production.

⚠️ Limitations and Considerations

• Material Suitability: Not all materials are compatible with thread rolling; brittle or highly hardened materials may not deform properly.

• Application Constraints: In environments such as sour gas service, the work-hardened surface can become a liability, potentially leading to stress corrosion cracking or reduced performance under harsh chemical exposure.

🔧 Thread Cutting Capabilities at SMI

At SMI, we’re fully equipped to cut a wide range of thread profiles to meet diverse application requirements. Our tooling supports:

• UNC (Unified Coarse)

• UNRC (Unified National Round Crest)

• UNF (Unified Fine)

• UNS (Unified Special)

• ACME and STUB ACME

• NPT (National Pipe Taper)

• Metric 60° Threads

Whether you're working with standard fasteners, pressure fittings, or custom thread forms, our precision machining ensures consistent quality and compliance with industry standards.

To ensure a threaded component meets design specifications, three critical dimensions must be verified:

• Major and Minor Diameters: These define the outermost and innermost boundaries of the thread profile.

• Pitch Diameter: The theoretical diameter where the thread thickness equals the space between threads—crucial for fit and engagement.

• Functional Diameter: Represents the effective size of the thread when assembled, accounting for tolerances and wear.

A combination of gauges is used to measure these parameters accurately:

• Outside and Inside Micrometers: For major and minor diameter checks.

• Pitch Diameter Micrometers and 3-Wire Method: For pitch diameter measurement.

• Plug and Ring Gauges: To verify go/no-go conditions and ensure compliance with standards.

• Multi-Rib Functional Roll Gauges: For assessing the thread’s performance under simulated operating conditions.

By integrating these tools, we can confidently validate that your threads conform to required specifications.