ASTM A194/A194M 2H Heavy Hex Nuts
API 6A 6D Flange Valve Wellhead ASME/ANSI Flange Heavy Hex Nuts
Dimension Standard: ASME B18.2.2, ASME B18.2.4.6M, ISO 4033, Din934 H=D
Inch Size: 1/4”-4”
Metric Size: M6-M100
Other Available Grade:
ASTM A194/A194M 2H, 2HM, 4, 4L, 7, 7L, 7M, 8, 8M, 16 and so on.
Finish: Plain, Black Oxide, Zinc Plated, Zinc Nickel Plated, Cadmium Plated, PTFE etc.
Packing: Bulk about 25 kgs each carton, 36 cartons each pallet
Advantage: High Quality, Competitive Price, Timely Delivery,Technical Support, Supply Test Reports
Please feel free to contact us for more details.
ASTM A194
The ASTM A194 specification covers carbon, alloy and stainless steel nuts intended for use in high-pressure and/or high-temperature service. Unless otherwise specified, the American National Standard Heavy Hex Series (ANSI B 18.2.2) shall be used. Nuts up to and including 1 inch nominal size shall be UNC Series Class 2B fit. Nuts over 1 inch nominal size shall be either UNC Series Class 2B fit or 8 UN Series Class 2B fit. High strength ASTM A194 grade 2H nuts are common in the marketplace and are often substituted for ASTM A563 grade DH nuts due to the limited availability of DH nuts in certain diameters and finishes. Grades| 2 | Carbon steel heavy hex nuts |
| 2H | Quenched & tempered carbon steel heavy hex nuts |
| 2HM | Quenched & tempered carbon steel heavy hex nuts |
| 4 | Quenched & tempered carbon-molybdenum heavy hex nuts |
| 7 | Quenched & tempered alloy steel heavy hex nuts |
| 7M | Quenched & tempered alloy steel heavy hex nuts |
| 8 | Stainless AISI 304 heavy hex nuts |
| 8M | Stainless AISI 316 heavy hex nuts |
Mechanical Properties Grade Identification Markings
| Grade Identification Marking5 | Specification | Material | Nominal Size, In. | Tempering Temp. °F | Proof Load Stress, ksi | Hardness Rockwell | See Note | |
| Min | Max | |||||||
| ASTM A194 Grade 2 | Medium Carbon Steel | 1/4 - 4 | 1000 | 150 | 159 | 352 | 1,2,3 | |
| ASTM A194 Grade 2H | Medium Carbon Steel, Quenched and Tempered | 1/4 - 4 | 1000 | 175 | C24 | C38 | 1,2 | |
| ASTM A194 Grade 2HM | Medium Carbon Steel, Quenched and Tempered | 1/4 - 4 | 1000 | 150 | 159 | 237 | 1,2,3 | |
| ASTM A194 Grade 4 | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 - 4 | 1100 | 175 | C24 | C38 | 1,2 | |
| ASTM A194 Grade 7 | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 - 4 | 1100 | 175 | C24 | C38 | 1,2 | |
| ASTM A194 Grade 7M | Medium Carbon Alloy Steel, Quenched and Tempered | 1/4 - 4 | 1100 | 150 | 159 | 237 | 1,2,3 | |
| ASTM A194 Grade 8 | Stainless AISI 304 | 1/4 - 4 | - | 80 | 126 | 300 | 4 | |
| ASTM A194 Grade 8M | Stainless AISI 316 | 1/4 - 4 | - | 80 | 126 | 300 | 4 | |
| NOTES: 1. The markings shown for all grades of A194 nuts are for cold formed and hot forged nuts. When nuts are machined from bar stock, the nut must additionally be marked with the letter 'B'. The letters H and M indicate heat treated nuts. 2. Properties shown are those of coarse and 8-pitch thread heavy hex nuts. 3. Hardness numbers are Brinell Hardness. 4. Nuts that are carbide-solution treated require additional letter A - 8A or 8MA. 5. All nuts shall bear the manufacturer’s identification mark. Nuts shall be legibly marked on one face to indicate the grade and process of the manufacturer. Marking of wrench flats or bearing surfaces is not permitted unless agreed upon between manufacturer and purchaser. Nuts coated with zinc have an asterisk (*) marked after the grade symbol. Nuts coated with cadmium shall have a plus sign (+) marked after the grade symbol. 6. Other less common grades exist, but are not listed here. Inch Fastener Standards. 7th ed. Cleveland: Industrial Fasteners Institute, 2003. N-80 - N-81. | ||||||||
| Element | 2, 2H, and 2HM | 4 | 7 and 7M (AISI 4140) | 8 (AISI 304) | 8M (AISI 316) |
|---|---|---|---|---|---|
| Carbon | 0.40% min | 0.40 - 0.50% | 0.37 - 0.49% | 0.08% max | 0.08% max |
| Manganese | 1.00% max | 0.70 - 0.90% | 0.65 - 1.10% | 2.00% max | 2.00% max |
| Phosphorus, max | 0.040% | 0.035% | 0.035% | 0.045% | 0.045% |
| Sulfur, max | 0.050% | 0.040% | 0.040% | 0.030% | 0.030% |
| Silicon | 0.40% max | 0.15 - 0.35% | 0.15 - 0.35% | 1.00% max | 1.00% max |
| Chromium | 0.75 - 1.20% | 18.0 - 20.0% | 16.0 - 18.0% | ||
| Nickel | 8.0 - 11.0% | 10.0 - 14.0% | |||
| Molybdenum | 0.20 - 0.30% | 0.15 - 0.25% | 2.00 - 3.00% |
Single-point threading, also colloquially called single-pointing (or just thread cutting when the context is implicit), is an operation that uses a single-point tool to produce a thread form on a cylinder or cone. The tool moves linearly while the precise rotation of the workpiece determines the lead of the thread. The process can be done to create external or internal threads (male or female). In external thread cutting, the piece can either be held in a chuck or mounted between two centers. With internal thread cutting, the piece is held in a chuck. The tool moves across the piece linearly, taking chips off the workpiece with each pass. Usually 5 to 7 light cuts create the correct depth of the thread.
The coordination of various machine elements including leadscrew, slide rest, and change gears was the technological advance that allowed the invention of the screw-cutting lathe, which was the origin of single-point threading as we know it today.
Today engine lathes and CNC lathes are the commonly used machines for single-point threading. On CNC machines, the process is quick and easy (relative to manual control) due to the machine’s ability to constantly track the relationship of the tool position and spindle position (called “spindle synchronization”). CNC software includes “canned cycles”, that is, preprogrammed subroutines, that obviate the manual programming of a single-point threading cycle. Parameters are entered (e.g., thread size, tool offset, length of thread), and the machine does the rest.
All threading could feasibly be done using a single-point tool, but because of the high speed and thus low unit cost of other methods (e.g., tapping, die threading, and thread rolling and forming), single-point threading is usually only used when other factors of the manufacturing process happen to favor it (e.g., if only a few threads need to be made,[6] if an unusual or unique thread is required, or if there is a need for very high concentricity with other part features machined during the same setup).
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