ASTM A193 B7 PTFE-Coated Stud Bolt with A194 2H Heavy Hex Nuts: High-Performance Fastening Solution

In petrochemical, power generation, and heavy industrial applications, reliable fastening components are essential for system integrity and safety. This PTFE-coated stud assembly, engineered by C&N, delivers exceptional performance in high-temperature, high-pressure, and corrosive environments. The assembly includes one double-ended stud and two heavy hex nuts, fully compliant with international standards.

Key Specifications

• Thread: 1-3/8″ diameter, 8 TPI (UN series), ASME B1.1 Class 2A/2B tolerance
• Dimensions: Stud overall length 280mm (approx. 11 inches), fully threaded
• Materials:
  • Stud: ASTM A193 Grade B7 alloy steel (tensile strength ≥ 861 MPa; yield strength ≥ 723 MPa)
  • Nuts: ASTM A194 Grade 2H carbon steel (optimized compatibility with B7)
• Surface Finish: PTFE (Polytetrafluoroethylene) coating for superior corrosion resistance and low friction
• Standards: ASME B18.2.1 (nuts), ASME B18.2.2 (studs), ASME B1.1 (threads)

Precision Manufacturing Process

C&N employs advanced techniques to ensure dimensional accuracy and superior mechanical properties:

1. Stud Production — Premium B7 alloy steel undergoes cold or hot heading, followed by CNC thread rolling. Rolled threads provide 15-20% higher fatigue strength than cut threads due to uninterrupted grain flow.
2. Heat Treatment — Quenching at 860°C and tempering at 620°C create a uniform tempered sorbite structure for excellent high-temperature stability and creep resistance.
3. Nut Production — Grade 2H blanks are cold-headed and tapped with precision thread chasers, maintaining tight clearances (0.02-0.05mm) for perfect stud mating.
4. PTFE Coating — Electrostatic spraying and high-temperature curing apply a 25-50μm coating with ASTM D3359 Class 5B adhesion.

Quality Inspection

Every assembly undergoes rigorous dimensional verification using precision instruments to guarantee compliance with ASME standards.

Performance Advantages & Applications

This stud assembly offers proven reliability in demanding conditions:

• Environmental Resistance → Operates reliably up to 427°C with outstanding protection against acids, alkalis, and chlorides thanks to PTFE coating.
• Secure Fastening → Full threading and double-end design resist vibration and shock loads in critical connections.
• Long Service Life → Precision manufacturing and low-friction coating reduce wear and maintenance needs.

Common applications include:

• Oil & gas drilling equipment
• Nuclear and thermal power pipelines
• Chemical reactors
• Pressure vessels and flange connections
• Heavy machinery

Selection & Installation Guidelines

• Match thread size, length, and material to operating pressure, temperature, and media.
• Clean threads thoroughly before installation.
• Engage fixed end 1.5–2 times nominal diameter.
• Apply torque per ASME guidelines or OEM specifications.

At C&N, we specialize in high-quality ASTM A193 B7/A194 2H stud assemblies and PTFE-coated fasteners. With strict quality control, competitive pricing, and rapid global delivery, we support projects worldwide in oil & gas, petrochemical, and power industries. Contact us today for custom solutions or a quick quote.