ASTM A193 Grade B7M Specifications
ASTM A193 Gr.B7M Full Thread Studs and Bolts: Importance and Application
Importance:
High tensile strength and toughness, suitable for high-pressure and high-temperature environments.
Excellent resistance to hydrogen embrittlement, ensuring long-term reliability in harsh conditions.
Application:
Used in the petrochemical industry for fastening components in reactors and pressure vessels.
Ideal for oil and gas applications, including drilling equipment and pipeline construction.
Chemical and Mechanical Requirements of AISI 4110
| Chemical Requirements | Elements | Range | Product Variation (Over or Under) |
|---|---|---|---|
| Carbon | 0.37 – 0.49 | 0.02 | |
| Manganese | 0.65 – 1.10 | 0.04 | |
| Phosphorus (max) | 0.035 | 0.005 over | |
| Sulphur (max) | 0.040 | 0.005 over | |
| Silicon | 0.15 – 0.35 | 0.02 | |
| Chromium | 0.75 – 1.20 | 0.05 | |
| Molybdenum | 0.15 – 0.25 | 0.02 |
| Mechanical Requirements (Inch Sizes [Metric Sizes]) | Diameter, Metric | Minimum Tempering Temperature (Fe/ºC) | Tensile Strength, Min (ksi [MPa]) | Yield Strength, Min, 0.2% Offset (ksi [MPa]) | Elongation in 4D, Min (%) | Reduction of Area, Min (%) |
|---|---|---|---|---|---|---|
| 4″ / M100 and under | ≤ 4″ / M100 | 1150 [620] | 100 [690] | 80 [550] | 18 | 50 |
| Over 4″ to 7″ / M100 – M175 | > 4″ / M100 – M175 | 1150 [620] | 100 [690] | 75 [515] | 18 | 50 |
| Hardness | Max. |
|---|---|
| 4″ / M100 and under | 235 HB / 99 HRB |
| Over 4″ to 7″ / M100 to M175 | 235 HB / 99 HRB |
| Process Carried Out | Stage | Description |
|---|---|---|
| Stage I | Hardening | at 880ºC for 2 hours in electric furnace. |
| Stage II | Quenching | in hot oil (60 to 95ºC). |
| Stage III | Hardness | as quenched (52/54 HRC). |
| Stage IV | Tempering | at 620ºC for 3 hours. |
| Stage V | Cooling | in air. |