ASTM A194 Grade 2H Heavy Hex Nuts
ASTM A194 Grade 2H Heavy Hex Nuts are industrial-grade nuts commonly used with ASTM A193 B7 stud bolts to form complete bolting assemblies for flange connections. Unlike standard hex nuts used for general fastening purposes, Grade 2H heavy hex nuts are manufactured with a heavier pattern, providing increased nut thickness and larger bearing surfaces for applications requiring stable tightening and reliable joint performance.
The heavy hex design allows these nuts to better match high strength stud bolts and provides improved contact between the nut, bolt and connected components. During installation, the larger wrenching dimensions allow proper tightening torque to be applied, helping maintain consistent clamping force in bolted flange joints. This makes ASTM A194 Grade 2H nuts widely selected for industrial equipment where connection reliability is important. ASTM A194 Grade 2H Heavy Hex Nuts are typically paired with ASTM A193 B7 stud bolts in applications such as oil and gas pipelines, petrochemical facilities, pressure vessels, power generation equipment and other industrial piping systems. Available in different sizes, thread configurations and surface finishes, these nuts can be supplied according to project requirements and assembly specifications.
Specification:
1. Diameter: The diameter of an A194 heavy hex nut refers to the size of the nut’s threaded hole. It is typically specified using a measurement like 1/2″, 5/8″, or 3/4″, indicating the inner diameter.
2. Grade: The grade 2H of an A194 heavy hex nut signifies its strength and material properties.
3. Material: These nuts are commonly made from carbon steel or alloy steel, depending on the grade, to meet specific strength and performance requirements.
4. Surface Treatment: Surface treatment refers to any coating or finish applied to the outer surface of the nuts
| Product name | A194 Grade 2H Heavy Hex Nuts |
|---|---|
| Standard | ASTM A194 |
| Diameter | 1/4"-4" |
| Thread: | UNC/UNF/8UN |
| Materials: | C45 STEEL |
| Grade: | 2H |
| Proof Load Stress: | 175KSI |
| Hardness: | C24-C38 |
| Marking: | 2H+Customer Brand |
| Dimension: | ASME B 18.2.2, ASME B 18.2.4.6M |
| Surface treatment: | Black Oxide Coating/Zinc Plating (Electroplating)/Hot-Dip Galvanizing/Mechanical Galvanizing/Dacromet Coating/Painting or Powder Coating |
| Application Industry | Construction/Bridges/Industrial Structures/Equipment and Machinery/Infrastructure |
Chemical Composition for A194 2H Heavy Hex Nuts:
| Chemical Elements | Composition |
|---|---|
| Carbon | 0.15 Min |
| Manganese | 1.00 Max |
| Phosphorus | 0.04 Max |
| Sulfur | 0.05 Max |
| Silicon | 0.4 Max |
Proof Load:
| Norminal Size | Thread Per Inch | Proof Load,lbf (Heavy Hex) | Proof Load,lbf (Hex) |
|---|---|---|---|
| 1/4″ | 20 | 5570 | 4770 |
| 5/16″ | 18 | 9170 | 7860 |
| 3/8″ | 16 | 13560 | 11620 |
| 7/16″ | 14 | 18600 | 15940 |
| 1/2″ | 13 | 24830 | 21280 |
| 9/16″ | 12 | 31850 | 27300 |
| 5/8″ | 11 | 39550 | 33900 |
| 3/4″ | 10 | 58450 | 50100 |
| 7/8″ | 9 | 80850 | 69300 |
| 1″ | 8 | 106000 | 90900 |
| 1 1/8″ | 8 | 138200 | 118500 |
| 1 1/4″ | 8 | 175000 | 150000 |
| 1 3/8″ | 8 | 215800 | 185000 |
| 1 1/2″ | 8 | 261100 | 223800 |
Dimension Chart of ASTM A194 Gr.2H Heavy Hex Nut:
The dimension chart of ASTM A194 Grade 2H Heavy Hex Nuts provides detailed dimensional information to help customers select the correct nut size for their bolting assemblies. Compared with standard hex nuts, heavy hex nuts have their own dimensional requirements, including larger width across flats, greater thickness and heavier body dimensions. These dimensions are important for ensuring proper fit and compatibility with matching stud bolts during installation.
The following dimension chart lists the commonly used specifications of ASTM A194 Grade 2H Heavy Hex Nuts, including nominal diameter, thread size, width across flats, width across corners and nut height. The dimensions are based on applicable ASME standards and are commonly used for matching ASTM A193 B7 stud bolts in flange bolting applications. Different sizes and thread configurations of ASTM A194 Grade 2H Heavy Hex Nuts can be supplied according to project requirements. Selecting the correct nut dimensions helps ensure proper engagement with the stud bolt threads, suitable tightening conditions and reliable assembly performance for industrial bolting systems.
| Mon | 3/8 | 1/2 | 9/16 | 5/8 | 3/4 | 7/8 | 1 | 1-1/8 | 1-1/4 | 1-3/8 | 1-1/2 | 1-5/8 | 1-3/4 | 1-7/8 | 2 | 2-1/4 | 2-1/2 | 2-3/4 | 3 | 3-1/4 | 3-1/2 | 3-3/4 | 4 |
| P | 16|24|32 | 13|20|28 | 12|18|24 | 11|18|24 | 10|16|20 | 9|14|20 | 8|12|20 | 7|12|18 | 7|12|18 | 6|12|18 | 6|12|18 | 6|12|18 | 5|8|12 | 6 | 4.5 | 4.5 | 4 | 4 | 4 | 4 | 4 | 4 | 4 |
| s min | 0.669 | 0.85 | 0.909 | 1.031 | 1.212 | 1.394 | 1.575 | 1.756 | 1.938 | 2.119 | 2.3 | 2.481 | 2.662 | 2.844 | 3.025 | 3.388 | 3.75 | 4.112 | 4.475 | 4.838 | 5.2 | 5.562 | 5.925 |
| s max | 0.688 | 0.875 | 0.938 | 1.062 | 1.25 | 1.438 | 1.625 | 1.812 | 2 | 2.188 | 2.375 | 2.562 | 2.75 | 2.938 | 3.125 | 3.5 | 3.875 | 4.25 | 4.625 | 5 | 5.375 | 5.75 | 6.125 |
| e min | 0.763 | 0.969 | 1.037 | 1.175 | 1.382 | 1.589 | 1.796 | 2.002 | 2.209 | 2.416 | 2.622 | 2.828 | 3.035 | 3.242 | 3.449 | 3.862 | 4.275 | 4.688 | 5.102 | 5.515 | 5.928 | 6.341 | 6.755 |
| e max | 0.794 | 1.01 | 1.083 | 1.227 | 1.443 | 1.66 | 1.876 | 2.093 | 2.309 | 2.526 | 2.742 | 2.959 | 3.175 | 3.392 | 3.608 | 4.041 | 4.474 | 4.907 | 5.34 | 5.774 | 6.207 | 6.64 | 7.073 |
| k min | 0.341 | 0.464 | 0.526 | 0.587 | 0.71 | 0.833 | 0.956 | 1.079 | 1.187 | 1.31 | 1.433 | 1.556 | 1.679 | 1.802 | 1.925 | 2.155 | 2.401 | 2.647 | 2.893 | 3.124 | 3.37 | 3.616 | 3.862 |
| k max | 0.377 | 0.504 | 0.568 | 0.631 | 0.758 | 0.885 | 1.012 | 1.138 | 1.251 | 1.378 | 1.505 | 1.632 | 1.759 | 1.886 | 2.013 | 2.251 | 2.505 | 2.759 | 3.013 | 3.252 | 3.506 | 3.76 | 4.014 |
Application of A194 Heavy Hex Nuts:
A194 heavy hex nuts are heavy hex nuts that are typically used in high-pressure and high-temperature applications. These nuts are made from carbon steel and have been heat-treated to achieve a specified hardness level. They are commonly used in conjunction with A193 B7 studs or bolts in industries such as oil and gas, power generation, and chemical processing.
The A194 heavy hex nuts offer excellent strength and durability, making them suitable for demanding environments where the joint must withstand extreme conditions. Their heavy hex design provides a larger bearing surface, distributing the load more evenly and reducing the risk of deformation or damage to the connected components.
These nuts are often employed in flange connections, where they help secure the flange to the pipe or equipment by applying the necessary clamping force. By using A194 heavy hex nuts in combination with A193 B7 studs or bolts, engineers can ensure reliable and robust connections that can withstand high stress and temperature variations.
Manufacturing Quality Control:
| Control Method | Detail |
|---|---|
| Material Inspection: | Verify the material's composition, heat treatment, and quality upon receipt. Conduct metallurgical analysis to ensure the material properties meet the standards. |
| Process Control: | Implement strict process control measures for heat treatment, machining, threading, and any other manufacturing steps. Maintain consistent process parameters to ensure uniform quality. |
| Inspection Points: | Introduce inspection points at various stages of manufacturing to check for defects, dimensions, and quality. Inspect threading, dimensions, surface finish, and other critical parameters. |
| Sampling and Testing: | Regularly sample products for testing, such as tensile testing, hardness testing, and metallurgical analysis, to ensure they meet the required specifications. |
| Thread Inspection: | Thoroughly inspect threading using proper thread gauges to ensure accurate dimensions and fit with mating components. |
| Traceability: | Implement a traceability system to track each fasteners journey from raw material to final product. This aids in accountability and recalls if necessary. |