The ASTM A194 Grade 7 performance specification is one of the specifications of nuts produced out of carbon, alloy and stainless steel that is designed to be utilized in high pressure and/or high temperature service applications. These are the equivalent of high-strength bolts that have matching nuts in critical assemblies. The standard dimensions of Grade 7 nuts vary with the ASTM standard unless otherwise stated, which is the American National Standard Heavy Hex Series (ANSI B 18.2.2).
As to thread fit, nuts to a nominal size of 1 inch should employ UNC Series Class 2B. In the case of larger nuts that are larger than 1- inch, the UNC Series Class 2B fit or the 8 UN Series Class 2B fit can be used. Since ASTM A194 Grade 7 nuts are much stronger and more easily available, when ASTM A563 Grade DH nuts are unavailable in particular diameter or finish, they are often used instead.
ASTM A194 Grade 7 Nuts and ASME SA194 Gr 7 Hex Nuts Manufacturer & Supplier in India
We are the major manufacturer and supplier of ASTM A194 Grade 7 and ASME SA 194 Gr 7 Hex Nuts and Heavy Hex Nuts in India. They are chromium molybdenum alloy steel high-performance internally threaded fasteners that have been closely heat-treated. The nut design is very convenient when it comes to tightening needs of high torque.
Grade 7 nuts of our production are of high material requirements and compositions would match with alloy steel grades like AISI 4140 and 4145H. The rivets are formed through either hot forging, cold forging or machining of a heat-treated bar stock. The quenching and tempering required to achieve a high hardness (usually 248 to 327BHN) and high tensile strength (150ksi to 175ksi) is achieved at 595 degrees Celsius. We provide a full size array, imperial 1/4 to 1/2 inches and metric M6 to M100.
These bolts are imperative in operations in harsh conditions in key industries, such as oil and gas, petrochemical, power generation and chemical industries. They are critical parts of such equipment as coolers, heat exchangers, condensers, and boiler uses. We would be most prepared to provide your normal or special order needs of these premium nuts and allied washers.
“Contact Jade Special Metals today with your requirement for ASTM A194 GR. 7 Nuts. We assure you of the best quote.”
ASTM A194 Grades
Table of Contents
- Types of ASTM A194 Grade 7 Nuts
- ASTM A194 Grade 7 Nuts Specification
- Chemical Composition of ASTM A194 GR 7 Nuts
- ASTM A194 Grade 7 Hex Nut Mechanical Properties
- ASTM A194 Gr 7 Nuts Dimensions Chart
- SA194 Grade 7 Hex Nut Dimension Chart
- ASTM A194 Gr 7 Lock Nut Size Chart
- ASTM A194 Gr. 7 Nuts Inventory
- Applications of ASTM A194 GR. 7 Nuts
Types of ASTM A194 Grade 7 Nuts
ASTM A194 Gr 7 Heavy Hex Nuts
ASTM A194 Gr 7 Hex Nuts
ASTM A194 Gr 7 Jam Nuts
ASTM A194 Grade 7 Washer
ASTM A194 Gr 7 Panel Nuts
ASTM A194 Gr 7 Wing Nuts
ASTM A194 Gr 7 Lock Nut
ASTM A194 Gr 7 T Nuts
ASTM A194 Gr 7 Square Nuts
ASTM A194 Gr 7 Nylon Insert Nuts
ASTM A194 Gr 7 Nyloc Nuts
ASTM A194 Grade 7 Nuts Specification
| Standards | Designation |
|---|---|
| ASTM | A194 Grade 7: Medium Carbon Chromium-Molybdenum Alloy Steel (AISI 4140 / 4142 / 4145H), Quenched and Tempered |
| Dimensions | ASME B18.2.2 (Heavy Hex Series) / ASME B18.2.1, B18.3 |
| Size Range — Imperial | 1/4″ to 4″ |
| Size Range — Metric | M6 to M100 |
| Heat Treatment | Quenched and Tempered at minimum 595°C (1100°F) |
| Hardness Range | 248–327 BHN / Rockwell HRC 24–35 |
| Melt Origin | South America / East Europe / Japan / Korea |
| Product Origin | Made in India |
| Threads Configuration | ASME B1.1 2A/3A Inch Unified Threads and B1.13M 6h Metric Coarse Threads |
| Certification | Dual Certified as per ASTM & ASME Codes |
| Additional Certifications | PED 97/23/EC Certified, Merkblatt AD 2000 W2 Certified |
| Mandatory Requirements | Free from Mercury & Radioactive Contamination |
| Additional Requirements | NACE MR0103 / MR0175 / ISO 15156 Compliance |
| Equivalent Grades | AISI 4140, AISI 4142, AISI 4145H, AISI 4140H |
* ASTM A194 Grade 7 nuts are often used as a substitute for ASTM A563 Grade DH nuts when the latter are unavailable in a specific diameter or finish.
** For sour gas / H2S service, specify Grade 7M — same material with mandatory NACE MR0175 / ISO 15156 hardness restriction.
Chemical Composition of ASTM A194 GR 7 Nuts
| Element | Symbol | ASTM A194 Grade 7 (%) |
|---|---|---|
| Carbon | C | 0.37 – 0.49% |
| Manganese | Mn | 0.65 – 1.10% |
| Silicon | Si | 0.15 – 0.35% |
| Phosphorus | P | 0.035% max |
| Sulfur | S | 0.040% max |
| Chromium | Cr | 0.75 – 1.20% |
| Nickel | Ni | — (not specified) |
| Molybdenum | Mo | 0.15 – 0.25% |
Note: The intentional addition of Bismuth (Bi), Selenium (Se), Tellurium (Te), and Lead (Pb) to the alloy is not permitted as per the ASTM A194 Grade 7 specification.
ASTM A194 Grade 7 Mechanical Properties, Hardness & Proof Load
| Nominal Size, In. | Temperature °F | Proof Load Stress, ksi | Hardness Rockwell | Material |
|---|---|---|---|---|
| 1/4 – 4 | 1100 | 80 | C38 | Medium Carbon Alloy Steel, Quenched and Tempered |
The temperature shown (1100°F) is the minimum HEAT TREATMENT temperature, not the service temperature. Grade 7 nuts are rated for service up to approximately 454°C (850°F).
Hardness Requirements
| Grade | Brinell Hardness (BHN) | Rockwell Hardness | Proof Load Stress (ksi) | Material |
|---|---|---|---|---|
| 7 | 248 – 327 BHN | HRC 24 – HRC 35 | 175 ksi (Heavy Hex) / 150 ksi (Hex) | Medium Carbon Alloy Steel, Quenched and Tempered |
Proof Load Table — Heavy Hex Nuts & Hex Nuts
| Nominal Size (Inch) | Proof Load — Heavy Hex Nuts (lbf) | Proof Load — Hex Nuts (lbf) |
|---|---|---|
| 1/4″ | 5,570 | 4,770 |
| 3/8″ | 13,560 | 11,620 |
| 1/2″ | 24,830 | 21,280 |
| 5/8″ | 39,550 | 33,900 |
| 3/4″ | 58,450 | 50,100 |
| 7/8″ | 80,850 | 69,300 |
| 1″ | 106,000 | 90,900 |
| 1-1/8″ | 138,200 | 118,500 |
| 1-1/4″ | 175,000 | 150,000 |
| 1-3/8″ | 215,800 | 185,000 |
| 1-1/2″ | 261,100 | 223,800 |
A: Based on proof stress of 175,000 psi for Heavy Hex Nuts | B: Based on proof stress of 150,000 psi for Hex Nuts
ASTM A194 Gr 7 Nuts Dimensions Chart
| Nominal Size or Basic Major Thread Diameter | F | G | H | ||||||
|---|---|---|---|---|---|---|---|---|---|
|
Width Across Flats |
Width Across Corners |
Thickness | |||||||
| Basic | Max | Min | Max | Min | Basic | Max | Min | ||
| 1/4 | .2500 | 7/16 | .438 | .428 | .505 | .488 | 7/32 | .226 | .212 |
| 5/16 | .3125 | 1/2 | .500 | .489 | .577 | .557 | 17/64 | .273 | .258 |
| 3/8 | .3750 | 9/16 | .562 | .551 | .650 | .628 | 21/64 | .337 | .479 |
| 7/16 | .4375 | 11/16 | .688 | .675 | .794 | .768 | 3/8 | .385 | .365 |
| 1/2 | .5000 | 3/4 | .750 | .736 | .866 | .840 | 7/16 | .448 | .427 |
| 9/16 | .5625 | 7/8 | .875 | .861 | 1.010 | .982 | 31/64 | .496 | .473 |
| 5/8 | .6250 | 15/16 | .938 | .922 | 1.083 | 1.051 | 35/64 | .559 | .535 |
| 3/4 | .7500 | 1-1/8 | 1.125 | 1.088 | 1.299 | 1.240 | 41/64 | .665 | .617 |
| 7/8 | .8750 | 1-5/16 | 1.312 | 1.269 | 1.516 | 1.447 | 3/4 | .776 | .724 |
| 1 | 1.0000 | 1-1/2 | 1.500 | 1.450 | 1.732 | 1.653 | 55/64 | .887 | .831 |
| 1-1/8 | 1.1250 | 1-11/16 | 1.688 | 1.631 | 1.949 | 1.859 | 31/32 | .999 | .939 |
| 1-3/8 | 1.3750 | 2-1/16 | 2.062 | 1.994 | 2.382 | 2.273 | 1-11/64 | 1.206 | 1.138 |
| 1-1/2 | 1.500 | 2-1/4 | 2.250 | 2.175 | 2.598 | 2.480 | 1-9/32 | 1.336 | 1.245 |
| 1-5/8 | 1.6250 | 2-7/16 | 2.438 | 2.356 | 2.815 | 2.686 | 1-25/64 | 1.429 | 1.353 |
| 1-3/4 | 1.7500 | 2-5/8 | 2.625 | 2.538 | 3.031 | 2.893 | 1-1/2 | 1.540 | 1.460 |
| 2 | 2.0000 | 3 | 3.000 | 2.900 | 3.464 | 3.306 | 1-23/32 | 1.763 | 1.675 |
| 2-1/4 | 2.2500 | 3-3/8 | 3.375 | 3.263 | 3.897 | 3.719 | 1-15/16 | 1.986 | 1.890 |
| 2-1/2 | 2.5000 | 3-3/4 | 3.750 | 3.625 | 4.330 | 4.133 | 2-5/32 | 2.209 | 2.105 |
| 2-3/4 | 2.7500 | 4-1/8 | 4.125 | 3.988 | 4.763 | 4.546 | 2-3/8 | 2.431 | 2.319 |
SA194 Grade 7 Hex Nut Dimension Chart
| Nominal Size or Basic Major Thread Diameter | F | G | H | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Width Across Flats | Width Across Corners | Thickness | |||||||
| Basic | Max | Min | Max | Min | Basic | Max | Min | ||
| 1/4 | .2500 | 1/2 | .500 | .488 | .577 | .556 | 15/64 | .250 | .218 |
| 5/16 | .3125 | 9/16 | .562 | .546 | .650 | .622 | 19/64 | .314 | .280 |
| 3/8 | .3750 | 11/16 | .688 | .669 | .794 | .763 | 23/64 | .377 | .341 |
| 7/16 | .4375 | 3/4 | .750 | .728 | .866 | .830 | 27/64 | .441 | .403 |
| 1/2 | .5000 | 7/8 | .875 | .850 | 1.010 | .969 | 31/64 | .504 | .464 |
| 9/16 | .5625 | 15/16 | .938 | .909 | 1.083 | 1.037 | 35/64 | .568 | .526 |
| 5/8 | .6250 | 1-1/16 | 1.062 | 1.031 | 1.227 | 1.175 | 39/64 | .631 | .587 |
| 3/4 | .7500 | 1-1/4 | 1.250 | 1.212 | 1.443 | 1.382 | 47/64 | .758 | .710 |
| 7/8 | .8750 | 1-7/16 | 1.438 | 1.394 | 1.660 | 1.589 | 55/64 | .885 | .833 |
| 1 | 1.0000 | 1-5/8 | 1.325 | 1.575 | 1.876 | 1.796 | 63/64 | 1.012 | .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 | 1.460 |
| 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 | 2.0000 | 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 | 3.0000 | 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 | 3.670 | 3.616 |
| 4 | 4.0000 | 6-1/8 | 6.125 | 5.925 | 7.073 | 6.755 | 3-15/16 | 4.014 | 3.862 |
“Contact Jade Special Metals today with your requirement for ASTM A194 GR. 7 Nuts. We assure you of the best quote.
ASTM A194 Gr 7 Lock Nut Size Chart
| Nuts Size (mm) |
Diameter* (mm) |
Height (mm) |
||
|---|---|---|---|---|
| Hex Nuts | Jam Nuts | Nylock Nuts | ||
| 2 | 4 | 1.6 | 1.2 | – |
| 2.5 | 5 | 2 | 1.6 | – |
| 3 | 5.5 | 2.4 | 1.8 | 4 |
| 4 | 7 | 3.2 | 2.2 | 5 |
| 5 | 8 | 4 | 2.7 | 5 |
| 6 | 10 | 5 | 3.2 | 6 |
| 7 | 11 | 5.5 | 3.5 | – |
| 8 | 13 | 6.5 | 4 | 8 |
| 10 | 17 | 8 | 5 | 10 |
| 12 | 19 | 10 | 6 | 12 |
| 14 | 22 | 11 | 7 | 14 |
| 16 | 24 | 13 | 8 | 16 |
| 18 | 27 | 15 | 9 | 18.5 |
| 20 | 30 | 16 | 10 | 20 |
| * This is the diameter across the flats. It is also the size of wrench to use. | ||||
Calculate the weight of your Grade 7 nut order using our Nuts Weight Calculator →
ASTM A194 GR. 7 Nuts Inventory
ASTM A194 GR. 7 Hex Nuts
ASTM A194 GR. 7 Lock Nuts
ASTM A194 GR. 7 Wing Nuts
Applications of ASTM A194 Grade 7 Nuts
- Oil & Gas/Petrochemical
- Power Generation
- Low-Temperature/Cryogenic Service
- Industrial Equipment
- Chemical/Biochemical
Countries We Export
We maintain ready stock of ASTM A194 GR. 7 Heavy Hex Nuts, Hex Nuts, Lock Nuts, Wing Nuts, and Self Locking Nuts. Get in touch for a same-day competitive quote.
