In March of this year, we quoted some stud bolts and nuts for customer from France. This client ordered several items in May and in July, they ordered ASTM A194 GR 8 Heavy Hex Nuts below as supplement. 1 week later, goods are ready to be picked up. Based on former experience, we packed the nuts every 50 pcs and shared photos to client. After confirming the shipping mark, the nuts are picked successfully.
Inspection Photos
For more orders on bolts and nuts, please click
- SS304 Stud Bolts and Nuts Order
- A320 L7 Stud Bolts with A194 Gr.7 Nuts Order
- ASTM A320 B8 Stud Bolts with A194 Gr.8 Nuts Order
ASTM A194 Gr.8 Stainless Steel Heavy Hex Nuts, SS 304
| Element | ASTM A194 Grade 8 |
| Carbon | 0.08 max |
| Manganese | 2.00 Max |
| Phosphorus, max | 0.05% |
| Sulfur, max | 0.03% |
| Silicon | 1.00% max |
| Chromium | 18.0-20.0% |
| Nickel | 8.0-11.0% |
| Molybdenum | – |
ASTM A194 Standards
This specification covers a variety of carbon, alloy, and martensitic stainless steel nuts in the size range 1⁄4 through 4 in. and metric M6 through M100 nominal. It also covers austenitic stainless steel nuts in the size range 1⁄4 in. and M6 nominal and above. These nuts are intended for high-pressure or hightemperature service, or both. Grade substitutions without the purchaser’s permission are not allowed.
Bars from which the nuts are made shall be hot-wrought. The material may be further processed by centerless grinding or by cold drawing. Austenitic stainless steel may be solution annealed or annealed and strain-hardened. When annealed and strain hardened austenitic stainless steel is ordered in accordance with Supplementary Requirement S1, the purchaser should take special care to ensure that 8.2.2, Supplementary Requirement S1, and Appendix X1 are thoroughly understood.
Stainless Steel ASTM A194 8/8M/8T Equivalent Grade
| Grade | Country | 304 | 304 L | 310 | 316 | 316 L |
| ASTM | America | ASTM A 193 Gr B8 | ASTM A 320 Ge B8 | ASTM A 479 | ASTM A 193 Gr B8T | ASTM A 320 Ge B8T |
| UNS | North America | S30400 | S30403 | S31000 | S31600 | S31603 |
| EN | European | 1.4301 | 1.4306 | 1.4841 | 1.4401 | 1.4404 |
| BS | British | BS 970 | BS 970 | BS 970 | BS 970 | BS 970 |
| DIN | German | X 5CrNi1810 | X 2CrNi1911 | X 12 CrNi 25 21 | X 5 CrNiMo 17 13 2 | X 2 CrNiMo 17 13 2 |
ASTM A194 Grade 8 Nuts Manufacturer and Exporter
ZIZI is a professional manufacturer and exporter of ASTM A194 Grade 8 heavy-duty hex nuts, dedicated to providing global customers with high-quality, high-strength fastener products. The company strictly adheres to ASTM A194 standards in production, with each nut undergoing precise inspection to ensure stable and reliable performance under high-temperature, high-pressure, and demanding conditions. Our products are widely used in petroleum, natural gas, chemical, and power industries, meeting customized requirements for diverse projects. We deliver to global markets safely and efficiently through international logistics.
ASTM A194 Grade 8 Nuts Proof Load Using Threaded Mandrel (Inch Series)
| Nominal Size, in. | Threads per Inch | Stress Area in. 2 | Proof Load, lbf A | |
| All Types of Grade 8 | ||||
| Heavy HexH | HexI | |||
| 1/4 | 20 | 0.0316 | 2 540 | 2 380 |
| 1/3 | 18 | 0.0524 | 4 190 | 3 930 |
| 3/8 | 16 | 0.0774 | 6 200 | 5 810 |
| 7/16 | 14 | 0.1063 | 8 500 | 7 970 |
| 1/2 | 13 | 0.1419 | 11 350 | 10 640 |
| 5/9 | 12 | 0.182 | 14 560 | 13 650 |
| 5/8 | 11 | 0.226 | 18 080 | 16 950 |
| 3/4 | 10 | 0.334 | 26 720 | 25 050 |
| 7/8 | 9 | 0.462 | 36 960 | 34 650 |
| 1/ | 8 | 0.606 | 48 480 | 45 450 |
| 1 1/8 | 8 | 0.79 | 63 200 | 59 250 |
| 1 1/4 | 8 | 1 | 80 000 | 75 000 |
| 1 3/8 | 8 | 1.233 | 98 640 | 92 450 |
| 1 1/2 | 8 | 1.492 | 119 360 | 111 900 |
ASTM A194 Grade 8 Nuts Proof Load Using Threaded Mandrel (Metric)
| Nominal Size, mm | Threads Pitch | Stress Area mm 2 | Proof Load, kNA | |
| All Types of Grade 8 | ||||
| Heavy Hex H | Hex I | |||
| M6 | 1 | 20.1 | 11.1 | 10.4 |
| M8 | 1.25 | 36.6 | 20.1 | 18.8 |
| M10 | 1.5 | 58 | 31.9 | 29.9 |
| M12 | 1.75 | 84.3 | 46.4 | 43.4 |
| M14 | 2 | 115 | 63.3 | 59.2 |
| M16 | 2 | 157 | 86.4 | 80.9 |
| M20 | 2.5 | 245 | 134.8 | 126.2 |
| M22 | 2.5 | 303 | 166.7 | 156 |
| M24 | 3 | 353 | 194.2 | 181.8 |
| M27 | 3 | 459 | 252.5 | 236.4 |
| M30 | 3.5 | 561 | 308.6 | 288.9 |
| M36 | 4 | 817 | 449.4 | 420.8 |
Gr8 A194 Heavy Hex Nuts 304 Stainless Dimension
| Heavy Hex Nuts:Dimensions(ANS/ASME B18.2.2) | |||||||||
| Nominal or Basic Major Diameter of Thread Click on the size to search products | Width Across Flats(F) | Width Across Corners(G) | Thickness of Hex Nuts(H) | ||||||
| Basic | Max | Min | Max | Min | Basic | Max | Min | ||
| 1/4 | 0.2500 | 1/2 | .500 | 488 | .577 | .556 | 15/64 | 0.250 | 0.218 |
| 5/16 | 0.3125 | 9/16 | 562 | 546 | 650 | 622 | 19/64 | 0.314 | 0.280 |
| 3/8 | 0.3750 | 11/16 | 688 | 669 | .794 | .763 | 23/64 | 0.377 | 0.341 |
| 7/16 | 0.4375 | 3/4 | .750 | .728 | .866 | 830 | 27/64 | 0.441 | 0.403 |
| 1/2 | 0.5000 | 7/8 | 875 | 850 | 1.010 | 969 | 31/64 | 0.504 | 0.464 |
| 9/16 | 0.5625 | 15/16 | .938 | 909 | 1.083 | 1.037 | 35/64 | 0.568 | 0.526 |
| 5/8 | 0.6250 | 1-1/16 | 1.062 | 1.031 | 1.227 | 1.175 | 39/64 | 0.631 | 0.587 |
| 3/4 | 0.7500 | 1-1/4 | 1.250 | 1.212 | 1.443 | 1.382 | 47/64 | 0.758 | 0.710 |
| 7/8 | 0.8750 | 1-7/16 | 1.438 | 1.394 | 1.660 | 1.589 | 55/64 | 0.885 | 0.833 |
| 1 | 1.0000 | 1-5/8 | 1.625 | 1.575 | 1.876 | 1.796 | 63/64 | 1.012 | 0.956 |
| 1-1/8 | 1.1250 | 1-13/16 | 1.812 | 1.756 | 2.093 | 2.002 | 1-7/64 | 1.139 | 1.079 |
| 1-1/4 | 1.2500 | 2 | 2.000 | 1.938 | 2.309 | 2.209 | 1-7/32 | 1.251 | 1.187 |
| 1-3/8 | 1.3750 | 2-3/16 | 2.188 | 2.119 | 2.526 | 2.416 | 1-11/32 | 1.378 | 1.310 |
| 1-1/2 | 1.5000 | 2-3/8 | 2.375 | 2.300 | 2.742 | 2.622 | 1-15/32 | 1.505 | 1.433 |
| 1-5/8 | 1.6250 | 2-9/16 | 2.562 | 2.481 | 2.959 | 2.828 | 1-19/32 | 1.632 | 1.556 |
| 1-3/4 | 1.7500 | 2-3/4 | 2.750 | 2.662 | 3.175 | 3.035 | 1-23/32 | 1.759 | 1.679 |
| 2 | 2.000 | 3-1/8 | 3.125 | 3.025 | 3.608 | 3.449 | 1-31/32 | 2.013 | 1.925 |
| 2-1/4 | 2.2500 | 3-1/2 | 3.500 | 3.388 | 4.041 | 3.862 | 2-13/64 | 2.251 | 2.155 |
| 2-1/2 | 2.5000 | 3-7/8 | 3.875 | 3.750 | 4.474 | 4.275 | 2-29/64 | 2.505 | 2.401 |
| 2-3/4 | 2.7500 | 4-1/4 | 4.250 | 4.112 | 4.907 | 4.688 | 2-45/64 | 2.759 | 2.647 |
| 3 | 3.000 | 4-5/8 | 4.625 | 4.475 | 5.340 | 5.102 | 2-61/64 | 3.013 | 2.893 |
| 3-1/4 | 3.2500 | 5 | 5.000 | 4.838 | 5.774 | 5.515 | 3-3/16 | 3.252 | 3.124 |
| 3-1/2 | 3.5000 | 5-3/8 | 5.375 | 5.200 | 6.207 | 5.928 | 3-7/16 | 3.506 | 3.370 |
| 3-3/4 | 3.7500 | 5-3/4 | 5.750 | 5.562 | 6.640 | 6.341 | 3-11/16 | 3.760 | 3.616 |
| 4 | 4.0000 | 6-1/8 | 6.125 | 5.925 | 7.073 | 6.755 | 3-15/16 | 4.014 | 3.862 |
ASTM A194 2H vs Grade 8 – What’s the Diffference
ASTM A194 2H and Grade 8 are both heavy-duty hex nuts primarily used for fastening applications in high-temperature, high-pressure, and demanding conditions. 2H nuts are typically made of alloy steel and undergo heat treatment, offering excellent tensile strength and high-temperature resistance. They are suitable for industries such as petroleum, chemical, and power generation. Grade 8 nuts offer slightly superior mechanical properties, with enhanced tensile strength and yield strength, enabling them to withstand greater load pressures.
Additionally, both differ in applicable standards and dimensions. 2H nuts are commonly used with bolts conforming to the ASTM A194 standard, while Grade 8 nuts are widely employed in SAE standard bolt systems. Selection should be based on the specific working environment, load requirements, and standard specifications to determine the most suitable nut grade.
Applications
Oil and gas piping systems
Pressure vessels and boilers
Power and energy industries
Chemical and petrochemical equipment
High-temperature and high-pressure flange connections
Advantages
High strength – Suitable for high-load applications.
High-temperature resistance – Maintains stable performance under high-temperature conditions.
Corrosion resistance – Alloying elements enhance corrosion resistance.
Various specifications – Customizable according to international standards and customer requirements.