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Hex Nut China Supplier
QS Fastener: Hex Nut China Supplier
Name: Hex Nut China Supplier
Material: ASTM A194 2H
Standard: ANSI B18.2.2
Coating: Teflon Coated for Corrosion Resistance
Type: Heavy Hex Type
Size: 1 Inch
Thread: 8 UN
Price: USD 2.99 - 9.99/ Kg
MOQ: 10kg
Customization: yes
Delivery time: 7-30 Day
Application: For High Strength Bolting
Material: ASTM A194 2H
Standard: ANSI B18.2.2
Coating: Teflon Coated for Corrosion Resistance
Type: Heavy Hex Type
Size: 1 Inch
Thread: 8 UN
Price: USD 2.99 - 9.99/ Kg
MOQ: 10kg
Customization: yes
Delivery time: 7-30 Day
Application: For High Strength Bolting
Quantity
The ASTM A194 2H heavy hex nut represents a benchmark in high-strength fastening technology. Manufactured in strict compliance with ANSI B18.2.2, this 1"-8UN nut is engineered to pair seamlessly with ASTM A193 B7 and B16 bolts, delivering lasting joint integrity in high-pressure pipelines, pressure vessels, heat exchangers, and heavy-duty rotating equipment. A proprietary Teflon coating is applied to reduce friction during make‑up, prevent galling, and provide robust corrosion resistance in marine, chemical, and sour‑gas environments.
When you source this component from a reliable China supplier, you benefit from full material traceability, rigorous dimensional inspection, and cost‑effective production without compromising quality—critical factors for both maintenance stock and large‑scale EPC projects.
High‑Temperature Performance Analysis
Based on systematic testing and engineering validation, the ASTM A194 2H heavy hex nut demonstrates clearly defined thermal behavior:
Based on systematic testing and engineering validation, the ASTM A194 2H heavy hex nut demonstrates clearly defined thermal behavior:
1. Strength Retention with Temperature Rise
Per GB/T 228.1‑2021 tensile tests:
- At 200°C, the nut retains approximately 95% of its room‑temperature yield strength, with grain‑boundary strengthening mechanisms actively contributing to stability.
- At 350°C for prolonged service, strength retention remains a solid 85%, though dynamic recovery begins to influence microstructural behavior.
- At the extreme limit of 425°C, retention drops sharply to about 70%; here, creep‑rupture assessment becomes mandatory for life‑cycle safety.
Per GB/T 228.1‑2021 tensile tests:
- At 200°C, the nut retains approximately 95% of its room‑temperature yield strength, with grain‑boundary strengthening mechanisms actively contributing to stability.
- At 350°C for prolonged service, strength retention remains a solid 85%, though dynamic recovery begins to influence microstructural behavior.
- At the extreme limit of 425°C, retention drops sharply to about 70%; here, creep‑rupture assessment becomes mandatory for life‑cycle safety.
2. Stress Relaxation Behavior (ASTM E328)
Simulated petrochemical duty cycles (350°C, 1,000 hours) reveal:
- Cumulative stress loss below 15%—significantly outperforming the 25% industry average for austenitic stainless steels.
- Transmission electron microscopy (TEM) shows M₂₃C₆ carbide precipitates with a spacing of ~150 nm, which effectively pin dislocations and retard relaxation.
- Per ASME BPVC‑III conversion factors, this translates to a reliable 100,000‑hour service life under typical operating loads.
Simulated petrochemical duty cycles (350°C, 1,000 hours) reveal:
- Cumulative stress loss below 15%—significantly outperforming the 25% industry average for austenitic stainless steels.
- Transmission electron microscopy (TEM) shows M₂₃C₆ carbide precipitates with a spacing of ~150 nm, which effectively pin dislocations and retard relaxation.
- Per ASME BPVC‑III conversion factors, this translates to a reliable 100,000‑hour service life under typical operating loads.
Engineering Conclusions & Practical Guidance
- Safe Operating Window: The ASTM A194 2H hex nut is fully qualified for continuous use up to 350°C. At 425°C, a 0.7 stress‑reduction factor must be applied in flange‑design calculations.
- Competitive Edge: Compared to 304 stainless steel equivalents, this carbon‑steel heavy hex nut reduces high‑temperature relaxation by roughly 40%, making it the preferred choice for thermal‑cycling services.
- In‑Service Inspection: In wet H₂S (sour) environments, we recommend ultrasonic examination every 2,000 operating hours to detect any early‑stage hydrogen‑induced damage.
- Safe Operating Window: The ASTM A194 2H hex nut is fully qualified for continuous use up to 350°C. At 425°C, a 0.7 stress‑reduction factor must be applied in flange‑design calculations.
- Competitive Edge: Compared to 304 stainless steel equivalents, this carbon‑steel heavy hex nut reduces high‑temperature relaxation by roughly 40%, making it the preferred choice for thermal‑cycling services.
- In‑Service Inspection: In wet H₂S (sour) environments, we recommend ultrasonic examination every 2,000 operating hours to detect any early‑stage hydrogen‑induced damage.
Typical Application Scenarios
- Oil & gas upstream (wellhead connectors, choke manifolds)
- Refinery hydroprocessing units (high‑temperature, high‑pressure flanges)
- Power generation (turbine casing bolting, steam lines)
- Chemical plants (aggressive media with temperature excursions)
- Structural steel connections in heavy industrial frameworks
- Oil & gas upstream (wellhead connectors, choke manifolds)
- Refinery hydroprocessing units (high‑temperature, high‑pressure flanges)
- Power generation (turbine casing bolting, steam lines)
- Chemical plants (aggressive media with temperature excursions)
- Structural steel connections in heavy industrial frameworks
Why Partner with a China Supplier?
Choosing a qualified China supplier for your ASTM A194 2H hex nuts ensures you receive competitive pricing, flexible MOQ (down to 10 kg), short lead times (7–30 days), and full customization—from special thread gauges to alternative coatings. Every batch is accompanied by a certified mill test report and, if required, third‑party inspection, so you can confidently use these nuts in critical bolted joints worldwide.
Choosing a qualified China supplier for your ASTM A194 2H hex nuts ensures you receive competitive pricing, flexible MOQ (down to 10 kg), short lead times (7–30 days), and full customization—from special thread gauges to alternative coatings. Every batch is accompanied by a certified mill test report and, if required, third‑party inspection, so you can confidently use these nuts in critical bolted joints worldwide.
FAQ ：
Q1: Can the ASTM A194 2H hex nut be used with B7 bolts at 400°C continuously?
Yes, but with caution. While the nut performs well up to 350°C, at 400–425°C we recommend applying a 0.7 stress‑reduction factor per ASME BPVC and performing periodic relaxation checks. For uninterrupted 400°C service, upgrading to a B16 bolt and reducing bolt preload is often advised.
Q1: Can the ASTM A194 2H hex nut be used with B7 bolts at 400°C continuously?
Yes, but with caution. While the nut performs well up to 350°C, at 400–425°C we recommend applying a 0.7 stress‑reduction factor per ASME BPVC and performing periodic relaxation checks. For uninterrupted 400°C service, upgrading to a B16 bolt and reducing bolt preload is often advised.
Q2: Is the Teflon coating suitable for offshore / saltwater environments?
Absolutely. The PTFE coating provides excellent barrier protection against chloride corrosion and significantly reduces thread galling during make‑up. However, care should be taken to avoid mechanical damage during handling; for long‑term subsea exposure, supplementary anodic protection or a thicker epoxy overlay may be considered.
Absolutely. The PTFE coating provides excellent barrier protection against chloride corrosion and significantly reduces thread galling during make‑up. However, care should be taken to avoid mechanical damage during handling; for long‑term subsea exposure, supplementary anodic protection or a thicker epoxy overlay may be considered.
Q3: How does this heavy hex nut compare to stainless steel 304 in high‑temperature relaxation?
Our tests show the ASTM A194 2H nut loses about 15% of initial stress after 1,000 hours at 350°C, whereas 304 stainless steel typically loses over 25% under identical conditions. This makes the 2H nut more reliable for thermal‑cycling applications where joint tightness is critical.
Our tests show the ASTM A194 2H nut loses about 15% of initial stress after 1,000 hours at 350°C, whereas 304 stainless steel typically loses over 25% under identical conditions. This makes the 2H nut more reliable for thermal‑cycling applications where joint tightness is critical.
Q4: What documentation and traceability does a typical China supplier provide?
A reputable China supplier will supply a mill test certificate (MTC) that includes chemical composition, hardness (HRC), proof load results, and dimensional compliance to ANSI B18.2.2. Additional services include third‑party testing (SGS/BV), ultrasonic examination records, and positive material identification (PMI) reports on request.
A reputable China supplier will supply a mill test certificate (MTC) that includes chemical composition, hardness (HRC), proof load results, and dimensional compliance to ANSI B18.2.2. Additional services include third‑party testing (SGS/BV), ultrasonic examination records, and positive material identification (PMI) reports on request.
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