Low Friction & Torque Accuracy
Reduces thread torque variability by over 60%, preventing thread seizing during high-speed hydraulic tensioning and makeup on large ASME B16.5 and B16.47 piping flanges.
ISO 9001:2015Precision dry film application
3,000+ Hrs Salt SprayASTM B117 salt fog tested
EN 10204 3.1 / 3.2Full coating thickness reports
Offshore ProvenSubsea & splash zone bolting
Engineering Specification
PTFE Fluorocarbon Coated Fasteners for Harsh Service
TorqBolt Inc. specializes in the precision application of PTFE (polytetrafluoroethylene) and advanced fluoropolymer dry-film resin coatings (including genuine Xylan 1070, Xylan 1024, and Xylar) to industrial stud bolts, hex bolts, heavy hex nuts, and washers. Designed specifically for critical offshore, chemical plant, marine, and subsea flange connections, PTFE coated fasteners eliminate breakout galling and withstand severe corrosive attacks.
Engineered fluorocarbon coatings create an impenetrable hydrophobic and oleophobic barrier that seals fastener substrates from contact with salt water, hydrogen sulfide, drilling fluids, and aggressive acids. With a coefficient of friction between 0.05 and 0.08, our coated fasteners guarantee uniform torque tensioning, predictable clamp loads, and easy non-destructive breakout even after years of continuous subsea immersion.
Technical Capabilities
Coating System & Performance Properties
Every coating batch applied at our manufacturing and processing facilities undergoes rigorous surface preparation, grit blasting, primer bonding, electrostatic spraying, and multi-stage heat curing.
Anti-Galling Protection
Prevents severe microscopic cold welding on stainless steel (304, 316, duplex) and nickel alloys (Inconel 718/625), ensuring smooth assembly and clean breakout without torch cutting.
Cryogenic to High-Temp Service
Retains continuous film flexibility and mechanical adhesion in harsh LNG and subsea deepwater extremes down to -195°C as well as high-temperature process lines up to +260°C.
| Test Standard | Exposed Reagent / Medium | Duration | Test Observation & Results |
|---|---|---|---|
| ASTM D1308 | Muriatic Acid (31% HCl) | 24 Hours | No film softening, bubbling, or substrate degradation |
| ASTM D1308 | Sulfuric Acid (93% H2SO4) | 24 Hours | No visual effect, zero loss of chemical integrity |
| ASTM D1308 | Caustic Soda (100% NaOH) | 24 Hours | No attack, complete alkali barrier maintained |
| ASTM D1308 | Methyl Ethyl Ketone (MEK) | 24 Hours | Unaffected, high solvent cross-link resistance |
| ASTM D1308 | Toluene & Hydrocarbon Solvents | 24 Hours | No film deterioration or adhesive loss |
| ASTM B117 | 5% Neutral Salt Fog Spray | 3,000+ Hours | Zero red rust on stud body and threaded engagement |
Manufacturing Integrity
Engineering Application Process
Reliable adhesion and salt spray performance demand uncompromising substrate preparation and temperature control across each coating stage.
Surface Preparation
Grit blasting with aluminum oxide to Sa 2.5 cleanliness, ensuring optimum surface profile depth (25-45 microns) for mechanical bonding.
Engineered Basecoat
Application of zinc phosphate or sacrificial metallic ceramic undercoat to ensure maximum cathodic protection in aggressive marine moisture.
Electrostatic Spraying
Automated precision spray application ensuring uniform dry film thickness (DFT) between 20 to 35 microns, preventing thread clearance interference.
Thermal Curing & QA
Convection oven baking at strictly managed ramps up to 400°C, followed by cross-hatch adhesion, thickness gauging, and MEK rub testing.
Technical FAQ
Frequently Asked Questions About PTFE Bolting
What are the primary operational benefits of PTFE fluorocarbon coated fasteners?
PTFE fluorocarbon coatings deliver three major technical benefits: a remarkably low friction coefficient (0.05 to 0.08) eliminating thread galling and ensuring accurate torque-tension conversion, exceptional corrosion resistance surpassing 3,000 to 4,000 hours in ASTM B117 salt spray tests, and inert barrier protection against aggressive chemicals, acids, and marine offshore atmospheres.
How does PTFE coating impact bolt makeup torque calculations?
Because PTFE dry film coating reduces the friction nut factor (k-factor) to approximately 0.08-0.12 compared to 0.18-0.22 for standard plain or cadmium-plated fasteners, tightening torque must be recalibrated downward. This ensures the intended bolt preload is reached precisely without yielding the bolt or overloading the flange joint.
What is the recommended operating temperature range for PTFE coatings?
Industrial fluorocarbon fastener coatings function continuously in temperatures ranging from cryogenic extremes of -195°C (-320°F) up to +260°C (+500°F). For short-term excursions, intermittent service up to +290°C (+554°F) is achievable without film breakdown.
What base undercoats are applied prior to the PTFE topcoat?
Depending on project specifications and corrosion requirements, TorqBolt applies an engineered base coat prior to fluoropolymer spraying and thermal curing. Common undercoats include zinc phosphate (standard), electro-deposited zinc-nickel, or ceramic base coats for maximum subsea sacrificial longevity.
Ready for Precision PTFE Coated Bolting?
Consult with our technical engineers for coating thickness tolerances, torque-tension curves, and customized mill test certifications to meet your project timeline.
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