Answer: ASTM A194 is a standard specification for carbon, alloy, and stainless steel nuts intended for use in high-pressure and/or high-temperature service.
Answer: The ASTM A194 specification covers various materials depending on the grade. For Grade 2H, the material is heat-treated carbon steel. Other grades within the specification cover alloy steels and stainless steels.
| 2 | Carbon steel heavy hex nuts |
|---|---|
| 2H | Quenched & tempered carbon steel heavy hex nuts |
| 2HM | Quenched & tempered carbon steel heavy hex nuts, 100% hardness tested |
| 4 | Quenched & tempered carbon-molybdenum heavy hex nuts (withdrawn in 2017) |
| 7 | Quenched & tempered alloy steel heavy hex nuts |
| 7M | Quenched & tempered alloy steel heavy hex nuts, 100% hardness tested |
| 7L | Quenched & tempered alloy steel heavy hex nuts, Charpy impact tested |
| 8 | Stainless AISI 304 heavy hex nuts |
| 8M | Stainless AISI 316 heavy hex nuts |
Answer: ASTM A194 Grade 2H is a specification for high-strength, heat-treated carbon steel nuts. They are quenched and tempered, making them suitable for high-pressure and high-temperature environments, and are commonly used with bolts like ASTM A193 Grade B7.
Answer: ASTM A194 Grade 2H nuts are produced in imperial sizes from 1/4" to 8" and in metric sizes from M6 to M180. They conform to dimensional standards such as ASME B18.2.2 for heavy hex nuts.
| olt Diam. | F | C | H | Weight | |||||
| Width Across Flats | Width Across Corners | Thickness | (lbs.) | ||||||
| Basic | Max | Min | Max | Min | Basic | Max | Min | ||
| 1⁄2 | 7⁄8 | 0.875 | 0.85 | 1.01 | 0.969 | 31⁄64 | 0.504 | 0.464 | 0.07 |
| 5⁄8 | 11⁄16 | 1.062 | 1.031 | 1.227 | 1.175 | 39⁄64 | 0.631 | 0.587 | 0.12 |
| 3⁄4 | 11⁄4 | 1.25 | 1.212 | 1.443 | 1.382 | 47⁄64 | 0.758 | 0.71 | 0.2 |
| 7⁄8 | 17⁄16 | 1.438 | 1.394 | 1.66 | 1.589 | 55⁄64 | 0.885 | 0.833 | 0.3 |
| 1 | 15⁄8 | 1.625 | 1.575 | 1.876 | 1.796 | 63⁄64 | 1.012 | 0.956 | 0.43 |
| 11⁄8 | 113⁄16 | 1.812 | 1.756 | 2.093 | 2.002 | 17⁄64 | 1.139 | 1.079 | 0.59 |
| 11⁄4 | 2 | 2 | 1.938 | 2.309 | 2.209 | 17⁄32 | 1.251 | 1.187 | 0.79 |
| 13⁄8 | 23⁄16 | 2.188 | 2.119 | 2.526 | 2.416 | 111⁄32 | 1.378 | 1.31 | 1.02 |
| 11⁄2 | 23⁄8 | 2.375 | 2.3 | 2.742 | 2.622 | 115⁄32 | 1.505 | 1.433 | 1.31 |
| 15⁄8 | 29⁄16 | 2.562 | 2.481 | 2.959 | 2.828 | 119⁄32 | 1.632 | 1.556 | 1.62 |
| 13⁄4 | 23⁄4 | 2.75 | 2.662 | 3.175 | 3.035 | 123⁄32 | 1.759 | 1.679 | 2.04 |
| 17⁄8 | 215⁄16 | 2.938 | 2.844 | 3.392 | 3.242 | 127⁄32 | 1.886 | 1.802 | 2.41 |
| 2 | 31⁄8 | 3.125 | 3.025 | 3.608 | 3.449 | 131⁄32 | 2.013 | 1.925 | 2.99 |
| 21⁄4 | 31⁄2 | 3.5 | 3.388 | 4.041 | 3.862 | 213⁄64 | 2.251 | 2.155 | 4.19 |
| 21⁄2 | 37⁄8 | 3.875 | 3.75 | 4.474 | 4.275 | 229⁄64 | 2.505 | 2.401 | 5.64 |
| 23⁄4 | 41⁄4 | 4.25 | 4.112 | 4.907 | 4.688 | 245⁄64 | 2.759 | 2.647 | 7.38 |
| 3 | 45⁄8 | 4.625 | 4.475 | 5.34 | 5.102 | 261⁄64 | 3.013 | 2.893 | 9.5 |
| 31⁄4 | 5 | 5 | 4.838 | 5.774 | 5.515 | 33⁄16 | 3.252 | 3.124 | 11.94 |
| 31⁄2 | 53⁄8 | 5.375 | 5.2 | 6.207 | 5.928 | 37⁄16 | 3.506 | 3.37 | 15.26 |
| 33⁄4 | 53⁄4 | 5.75 | 5.562 | 6.64 | 6.341 | 311⁄16 | 3.76 | 3.616 | 18.12 |
| 4 | 61⁄8 | 6.125 | 5.925 | 7.073 | 6.755 | 315⁄16 | 4.014 | 3.862 | 21.8 |
| Dimensions per ASME B18.2.2 1987 (1999) | |||||||||
Answer: Metric ASTM A194 Grade 2H nuts are available from size M6 to M180.
Answer: The typical chemical composition of ASTM A194 Grade 2H is as follows:
| Element | Carbon | Manganese | Phosphorus, max | Sulfur, max | Silicon | Chromium | Nickel | Molybdenum | - |
| 2H | 0.40% min | 1.00% max | 0.04% | 0.05% | 0.40% max | - | - | - | - |
Answer: The primary differences between ASTM A194 2H and 2HM are in testing, hardness, and proof load requirements, while their chemical composition is the same.
Testing: Grade 2H requires sample-based hardness testing, while Grade 2HM requires 100% of nuts to be hardness tested.
Hardness: Grade 2H has a higher hardness range (248-327 HB) compared to Grade 2HM (159-235 HB).
Proof Load: Grade 2H has a higher proof load requirement than Grade 2HM.
Marking: The nuts are marked "2H" or "2HM" for identification.
| Grade Identification Marking5 | Specification | Material | Nominal Size, In. | Tempering Temp. °F | Proof Load Stress, ksi | Hardness Rockwell | See Note | |
|---|---|---|---|---|---|---|---|---|
| Min | Max | |||||||
 |
ASTM A194 Grade 2H | Medium Carbon Steel, Quenched and Tempered | 1/4 - 4 | 850 | 175 | C24 | C38 | 1,2 |
 |
ASTM A194 Grade 2HM | Medium Carbon Steel, Quenched and Tempered | 1/4 - 4 | 1150 | 150 | 159 | 237 | 1,2,3 |
Answer: ASTM A194 Grade 2H is a carbon steel nut specification for high-temperature service, while Grade 8 typically refers to a high-strength bolt grade. One source indicates that ASTM A194 2H has a higher yield strength (100 ksi) compared to Grade 8 (36 ksi) and is suited for much higher temperature applications.
Answer: The main difference between ASTM A194 Grade 2H and ASTM A563 Grade DH nuts lies in their typical applications.
A194 Grade 2H: Primarily used in high-pressure and high-temperature services, such as in the oil, gas, and petrochemical industries for flanges, valves, and pressure vessels.
A563 Grade DH: While also high-strength, it is more commonly used in structural applications like steel frames and bridges, and is often paired with ASTM A325 or A490 bolts.
Answer: Fullerkreg uses material grades like EN8, EN8D, or AISI 1045 carbon steel for manufacturing A194 Grade 2H nuts.
Answer: The provided reference materials do not contain links to or information about obtaining a PDF document for the ASTM A194 Grade 2H specification.
Answer: Yes, according to the provided materials, Fullerkreg is a manufacturer of ASTM A194 Grade 2H nuts, producing them as standard hex or heavy hex nuts. they produced in china.
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A194 2H Nut Dimensions
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A194 2H vs A563 | A194 2H vs Grade 8 |
| ASTM A194 | ASTM A194 Grade 2H chemical composition | ASTM A194 Grade 2H pdf |
| PIC | PRODUCT | SIZE | GRADE | FINISH | THREAD |
 |
Heavy Hex Nut, A194 Grade 2H - Plain Finish | M8 to M95 | A194 2H | Black | Coarse Full |
|
Heavy Hex Nut, A194 Grade 2H - Hot Dip Galvanized | 3/8″ to 4″ | A194 2H | Black | Coarse Full |