ASTM A320 L7M Stud bolt HDG Hot Dip Galvanized
ASTM A320 L7M Stud bolt HDG Hot Dip Glavanized Hext nuts manufacturer in China
ASTM A320Material and Grade (L7M):Enhanced toughness and ductility are required for temperatures as low as -150°F (-101°C).
L7M refers to alloy steel used in stud bolts per ASTM A320, designed for cryogenic and low-temperature applications.
Typical material includes chromium-molybdenum steel (4140 )
ASTM A320 L7M stud bolt A194 7M Heavy Hex nuts Supply Scope:
FULL-THREAD, 8-UN, ASME B18.2.1/B1.1 CL.2A/ A194/A194M-7M, WITH TWO HEAVY HEX. NUTS, ASME B18.2.2/B1.1 CL.2B,
BOLT, StdBlt, A320L7M/7M, Stud Bolt – Threaded Full Length Alloy Steel Per ASTM A320-L7M with Three Carbon Steel Nuts Per A194-7M Threads to ISO Metric DIN 13 with Nuts to DIN 934
| Standard: | ANSI/ASME B 18.31.2,DIN975/DIN976, |
| Diameter: | 1/4″-5″,M6-M125 |
| Length: | ≤9m |
| Material: | ASTM A320 L7M stud bolt |
Hot-Dip Galvanizing (HDG):
Hot-dip galvanization is a form of galvanization. It is the process of coating iron and steel with zinc, which alloys with the surface of the base metal when immersing the metal in a bath of molten zinc at a temperature of around 450 °C (842 °F).
The stud bolt must comply with ASTM A320 L7M for material and mechanical properties.
The galvanizing process must meet ASTM A153 or ASTM F2329 standards for hot-dip galvanizing.
ASTM A320 L7M stud bolt with hot-dip galvanizing (HDG) is a specialized fastener designed for low-temperature environments with added corrosion protection
chemical composition range for Grade L7M bolts:
| Element | Percentage (%) |
|---|---|
| Carbon (C) | 0.37 max |
| Manganese (Mn) | 0.65–1.10 |
| Phosphorus (P) | 0.035 max |
| Sulfur (S) | 0.040 max |
| Silicon (Si) | 0.15–0.35 |
| Chromium (Cr) | 0.75–1.20 |
| Molybdenum (Mo) | 0.15–0.25 |
| Vanadium (V) | 0.03 max |
Mechanical Properties:
- Tensile Strength: Minimum 105 ksi (724 MPa).
- Yield Strength: Minimum 75 ksi (517 MPa).
- Elongation: Minimum 20% (measured on a standard 2-inch gauge length).
- Reduction of Area: Minimum 50%.
- Charpy Impact Test:
- Ensures performance at low temperatures, typically down to -150°F (-101°C).
Heat Treatment:
- ASTM A320 L7M stud bolt Bolts must be quenched and tempered to achieve the required mechanical properties and toughness.
Surface Treatment
- Hot-Dip Galvanizing (HDG) is often applied for enhanced corrosion resistance in harsh environments.
Hot-dip galvanization is a form of galvanization. It is the process of coating iron and steel with zinc, which alloys with the surface of the base metal when immersing the metal in a bath of molten zinc at a temperature of around 450 °C (842 °F).
Hot dip galvanized ASTM A320 L7M stud bolt according ASTM F2329 is the most common grade of anti-rust stud bolts.
