Description
ASTM A194 2H Heavy Hex Nut
ASTM A194 2H Nuts: High-Strength Fasteners for Extreme Conditions
Overview of ASTM A194 2H Heavy Hex Nuts
The ASTM A194 2H Heavy Hex Nut is a high-strength, durable fastener designed for applications requiring resistance to high pressure and extreme temperatures. Manufactured from carbon steel, alloy steel, and martensitic or austenitic stainless steel, these nuts provide exceptional performance in critical industries such as petrochemical, oil and gas, power generation, and construction.
Manufacturing Process & Material Properties
Raw Material & Processing
- Hot-wrought bars are used to ensure superior strength and durability.
- Centerless grinding and cold drawing are additional processing methods used to enhance precision and surface finish.
- Austenitic stainless-steel nuts undergo various treatments, including solution annealing, standard annealing, and strain hardening, to improve mechanical properties.
Quality & Testing Standards
To meet ASTM A194 2H specifications, nuts must comply with strict chemical composition standards for strength and corrosion resistance. Each batch undergoes:
- Hardness testing to ensure compliance with the required HRC and HBW range.
- Proof load and cone proof load testing to verify strength and load-bearing capacity.
Dimensional & Threading Specifications
Size & Fit
- Up to 1-inch nominal size: Uses UNC Series Class 2B fit for secure fastening.
- Above 1-inch nominal size: Available in UNC Series Class 2B fit or 8 UN Series Class 2B fit, offering flexibility across industrial applications.
- Complies with ANSI B18.2.2, ensuring precision in size and compatibility with high-strength bolts.
Key Applications of ASTM A194 2H Heavy Hex Nuts
These high-performance nuts are commonly used in industries that demand exceptional durability and strength.
Oil & Gas Pipelines
- Used in offshore and onshore oil rigs, refinery operations, and gas processing plants.
Structural Steel & Construction
- Provides stability in bridges, high-rise buildings, and heavy equipment installations.
Power Generation
- Essential in nuclear, thermal, and renewable energy plants, where extreme heat and pressure exist.
Chemical & Petrochemical Processing
- Designed for high-temperature, corrosive environments, ensuring long-lasting performance in chemical plants.
Why Choose ASTM A194 2H Nuts?
- Superior Strength & Durability – Engineered for high-pressure and high-temperature environments.
- Versatile Threading Options – Available in UNC and 8 UN Series to accommodate diverse applications.
- Corrosion Resistance – Manufactured from high-quality materials with various protective coatings.
- Industry Compliance – Meets ASTM, ANSI, and ASME standards, ensuring reliability in engineering projects.
Mechanical Properties of ASTM A194 2H Heavy Hex Nuts
The ASTM A194 2H specification ensures these nuts meet stringent strength, hardness, and durability requirements.
| Property | ASTM A194 2H Requirement |
|---|---|
| Proof Load | 175,000 psi (1205 MPa) |
| Hardness (HRC) | 24–38 HRC |
| Hardness (Brinell HBW) | 248–352 HBW |
| Impact Toughness | Not required but available upon request |
Chemical Composition of ASTM A194 2H Heavy Hex Nuts
Made from medium carbon steel, these nuts undergo quenching and tempering to achieve the required strength.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.40 – 0.50 |
| Manganese (Mn) | 0.60 – 1.35 |
| Phosphorus (P) (max) | 0.04 |
| Sulfur (S) (max) | 0.05 |
Heat Treatment Process
To ensure high strength and durability, ASTM A194 2H nuts undergo:
- Quenching and tempering – Enhances strength, toughness, and wear resistance.
- Hardness Testing – Ensures nuts remain within the required hardness range (24–38 HRC).
Dimensional & Standard Compliance
- Size Range: ¼” to 4” (UNC & 8 UN Threads).
- Thread Fit: UNC Series Class 2B (up to 1”) and UNC or 8 UN Series Class 2B (over 1”).
- Standard Compliance: Conforms to ANSI B18.2.2 (American National Standard for Heavy Hex Nuts).
Surface Finish & Coatings for Corrosion Resistance
Different finishes and coatings provide protection based on the application:
- Plain (Uncoated) – Ideal for dry indoor applications.
- Hot-Dip Galvanized (HDG) – Provides superior corrosion resistance, especially in marine and outdoor environments.
- Zinc-Plated – Offers moderate corrosion resistance and a smooth finish.
- Xylan/PTFE Coated – Reduces friction and enhances chemical resistance, commonly used in oil & gas applications.
Substitution & Market Availability
Due to their superior strength and widespread availability, ASTM A194 2H heavy hex nuts are often substituted for ASTM A563 Grade DH nuts, especially when DH nuts are not available in certain sizes or finishes.
Ordering ASTM A194 2H Heavy Hex Nuts
For businesses and engineers seeking high-performance fasteners, ASTM A194 2H heavy hex nuts provide a cost-effective and reliable solution.
📞 Contact us today for technical support, bulk orders, and pricing details!
ASTM A194 2H Heavy Hex Nut
