HOT DIP GALVANIZED A193 B7M STUD BOLT MANUFACTURER
ASTM A193 Grade B7M Stud Bolt with ASTM A194 Grade 2HM Heavy Nuts – Hot Dip Galvanized
We are a professional manufacturer and global supplier of ASTM A193 Grade B7M stud bolts with ASTM A194 Grade 2HM heavy hex nuts, supplied with hot dip galvanized (HDG) coating for enhanced corrosion resistance.
This bolting combination is specifically designed for high-pressure, high-temperature, and corrosive service, particularly in oil & gas, petrochemical, refinery, offshore, and power plant applications.
B7M / 2HM fasteners are commonly specified for sour service and critical flange connections where controlled hardness and reliable performance are required.
ASTM A193 B7M is a modified, lower hardness version of B7 used primarily in sour gas (H₂S) environments to prevent hydrogen embrittlement. the stud bolt of B7M grade commonly used in oil & gas, petrochemical, and refinery applications
Product Range – B7M Stud Bolts with 2HM Nuts
- Fully threaded stud bolts
- Double end stud bolts
- Tap end stud bolts
- Custom threaded rods
Diameter: ½” – 4″ (M12 – M100)
Length: Up to 3000 mm
Thread Type: UNC / UNF / Metric
Nut Type: Heavy Hex Nuts (ASTM A194 Grade 2HM)
All fasteners are supplied as complete sets (stud bolt + 2 heavy nuts).
Bolt Material Standard & Grade
- Standard: ASTM A193
- Grade: B7M
- Material: Chromium-Molybdenum Alloy Steel
- Heat treatment: Quenched & Tempered
Mechanical Properties of B7M stud bolt
| Property | ASTM A193 B7M Requirements |
|---|---|
| Tensile Strength | 100 ksi (690 MPa) min |
| Yield Strength | 80 ksi (550 MPa) min |
| Hardness | 235 HBW max (Rockwell C22 max) |
Hot-Dip Galvanizing (HDG) Specification
Hot-dip galvanizing (HDG) is the process of coating fabricated steel by immersing it in a bath of molten zinc.
Hot-dip galvanizing involves dipping steel into a zinc smelter at approx. 450°C following the appropriate pre-treatment. Zinc and steel will then react with one another. An iron-zinc alloy will form on the surface of the steel. This indissoluble compound of zinc and steel creates a protection, which is clearly different from all other processes. Hot-dip galvanized surfaces are not just protected from wind and the weather but also ideally protected from mechanical exposure – for decades to come. Under normal conditions, hot-dip galvanizing will protect against corrosion for up to 50 years and generally more than 25 years in the case of higher exposure levels.
Standard: ASTM A153 / ASTM F2329
Standard Specification for Zinc Coating (Hot-Dip) on Iron and Steel Hardware
Coating Process: Zinc coating applied via hot-dip galvanization (HDG)
Coating Thickness: Typically 1.7 – 3.4 mils (43 – 86 µm)
Thread Standards & Dimensions
- Thread Type: UNC (Coarse), UNF (Fine), Metric (ISO)
- Thread Standard: ASME B1.1 (Inch), ASME B1.13M (Metric)
- Stud Bolt Dimensions: ASME B18.2.1 / B18.31.2
- Nut Compatibility: ASTM A194 Gr. 2HM (galvanized) or A563 DH (oversized tapped for HDG coating)
Applications of B7M HDG Fasterner
- Oil & Gas (Sour Gas / H₂S Environments)
- Petrochemical & Refineries
- Offshore & Marine Industry
- High-temperature & pressure applications
Hot Dip Galvanized (HDG) Coating
The hot dip galvanizing process provides a thick zinc coating that offers long-term corrosion protection in aggressive environments.
| Property | Typical Value |
|---|---|
| Coating Standard | ASTM A153 / ISO 1461 |
| Coating Thickness | 50–85 μm |
| Corrosion Resistance | Excellent |
| Outdoor / Marine Use | Suitable |
Typical Description of STUD BOLT A193 GR. B7M HOT DIP GALVANIZED ASTM A153
STUD BOLT +2 HEAVY NUTS, A193 GR. B7M – A194 GR. 2HM, HOT DIP GALVANIZED ACC. TO ASTM A153 (TO FLANGE 1.1/2″)
Materia:ASTM A193 GR. B7M, ASTM A194 GR. 2HM, HOT DIP GALVANIZED
ASME B1.1 (UNC <= 1″ & 8 UN =>1 1/8) ASME 18.2.2/1
1″ Size ” Length = 6 1/4″
We also supply PTFE Coated ASTM A193 B7 Stud bolt
