| Standard | ASTM A193 · A193M Grade B7 stud; ASTM A194 / A194M Grade 2H nut; ASME B18.31.2; ASME B18.2.2 Table 10 |
|---|---|
| Material | Chromium-molybdenum alloy steel stud with carbon steel nut |
| Strength Grade | ASTM A193 Grade B7 + ASTM A194 Grade 2H |
| Size Range | 1/4 in-4 in; metric sizes by drawing or purchase specification |
| Surface Treatment | Plain / Black Oxide / PTFE / zinc or project-specified coating |
Product Description
The B7 and 2H combination is a common matched bolting assembly for pressure flanges, valves, piping and equipment. The stud is chromium-molybdenum alloy steel to ASTM A193/A193M Grade B7; the companion nut is carbon steel to ASTM A194/A194M Grade 2H.
Stud geometry is supplied to ASME B18.31.2 and the heavy hex nut geometry to ASME B18.2.2 Table 10. The thread series, nominal diameter, stud length, surface finish and washer requirement are confirmed together so the supplied components fit the project joint.
Each order can be supported with heat and lot traceability, material certificates, dimensional inspection and certificates of conformance. Coating and lubrication choices should be reviewed with the design temperature, installation method and project specification.
| Assembly | Full-thread stud bolt with matching heavy hex nut; washer included when specified |
|---|---|
| Stud material | Chromium-molybdenum alloy steel, ASTM A193/A193M Grade B7 |
| Nut material | Carbon steel, ASTM A194/A194M Grade 2H |
| Stud dimensional standard | ASME B18.31.2 |
| Nut dimensional standard | ASME B18.2.2 Table 10, heavy hex |
| Thread | UNC, UNF or metric thread to purchase specification; mating thread fit verified |
| Size and length | Diameter, thread and stud length confirmed per purchase order or approved drawing |
| Surface finish | Plain, black oxide, PTFE, zinc, HDG or project-specified coating |
| Optional washer | ASTM F436 hardened washer or other project-specified washer |
| Quality documents | MTC / CMTR, CoC, dimensional report and heat or lot traceability available by request |
Selection
A B7 stud with a Grade 2H heavy hex nut is widely specified for refinery, petrochemical and process piping flange joints. Confirm coating, lubrication, temperature and any sour-service requirement in the project specification.
Oil and gas fastenersMatched studs and heavy hex nuts simplify valve, pressure vessel and heat exchanger procurement by keeping thread, material grade and documentation requirements together.
Industrial equipment fastenersB7 and 2H assemblies can be supplied for high-temperature piping and equipment when the design code and operating temperature accept the specified material pair.
Power generation fastenersAssembly
Manufacturing
FAQ
The standard set includes a full-thread ASTM A193 Grade B7 stud and matching ASTM A194 Grade 2H heavy hex nut(s). Washers are included when stated in the purchase specification.
Yes. Confirm the nominal diameter, thread series, stud length, nut quantity per stud and washer requirement for quotation.
Material certificates, certificates of conformance, dimensional records and heat or lot traceability can be supplied according to the order requirements.
Do not assume sour-service compliance from the B7 and 2H grades alone. NACE and project requirements must be specified and verified separately.
Send the diameter, thread, stud length, quantity per set, coating, washer requirement and inspection documents needed for your project.
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