ASTM A194 2H Heavy Hex Nut — ASTM A194 2H

Description

1. Product Overview

The ASTM A194 2H Heavy Hex Nut is a high-tensile, heat-treated carbon steel fastener engineered for critical bolting applications in high-pressure and high-temperature industrial environments. Its primary use is securing flanges, valves, pressure vessels, and piping systems in oil & gas, petrochemical, power generation, and heavy construction sectors. The key value proposition lies in its quenched-and-tempered material structure, which delivers exceptional proof load capacity (175,000 psi for heavy hex) and Rockwell C hardness (24–35), ensuring reliable performance under extreme stress. Strategically, this nut is indispensable for enterprise sourcing because it meets rigorous ASTM standards for safety and durability, reducing failure risk in mission-critical infrastructure.

2. Key Specifications & Technical Characteristics

• Material Composition: Medium carbon steel (heat-treated)

  • Carbon: ≥0.40%

  • Manganese: ≤1.00%

  • Phosphorus: ≤0.040%

  • Sulfur: ≤0.040%

  • Silicon: ≤0.40%

• Grade: ASTM A194 Grade 2H (quenched and tempered at ≥850°F/455°C)

• Physical Characteristics:

  • Form: Heavy hexagon shape (asper ASME B18.2.2 Table 10 for imperial; ASME B18.2.4.6M for metric)

  • Size Range: 1/4″ to 8″ (imperial); M6 to M180 (metric)

  • Hardness: Brinell 212–327 BHN; Rockwell C 24–35 HRC

  • Tensile Strength: ~1,000 MPa (145 ksi)

• Packaging Options: Bulk drums, tagged bundles, or custom industrial packaging (moisture-resistant)

• Shelf Life: Indefinite when stored in dry conditions (no degradation of heat-treated properties)

3. Core Industrial Applications

• Primary Industries: Oil & gas extraction/refining, petrochemical processing, power generation (thermal/hydro), heavy infrastructure, and pressure system manufacturing

• Specific Use Cases:

  • Securing high-pressure flange connections in pipeline systems

  • Anchoring valves and fittings in reactor vessels

  • Fastening structural components in seismic-resistant buildings

• Performance Advantages:

  • Superior to ASTM A563 Grade DH nuts in high-temperature service due to stricter heat-treatment requirements

  • 175,000 psi proof load capacity (heavy hex) exceeds standard hex nuts (150,000 psi), preventing bolt loosening under cyclic stress

  • Enhanced durability from quenched-and-tempered process reduces replacement frequency by 30–40% in harsh environments

4. Competitive Advantages

5. Commercial & Supply Information

• Minimum Order Quantity (MOQ): BULK 20MT

• Loading Capacity: 20MT per 40’HQ container (optimized for heavy-density shipping)

• Lead Time: 7–10 days for standard sizes; 14 days for custom metric ranges