China ASTM A325 Type 1 Heavy Hex Structural Bolts,A325 Hex bolt manufacturer
ASTM A325 is an ASTM International standard for heavy hex structural bolts, titled Standard Specification for Structural Bolts, Steel, Heat Treated, 120/105 ksi Minimum Tensile Strength. It defines mechanical properties for bolts that range from 1⁄2 to 11⁄2 inches (13 to 38 mm) in diameter.
ASTM A325 bolts are heavy hex bolts made of medium carbon steel with a flat bearing surface, washer faced, and chamfered point. A325 bolts are partially threaded for precise grip in structural joints. These bolts are one of the most common heavy hex fasteners, usually used for structural support in steel construction. Used with matching nuts, these bolts come in a black oxide finish or are hot-dipped galvanized for added corrosion resistance. Black oxide coatings are corrosion resistant in dry environments. Hot-dipped galvanized steel coatings are more corrosion resistant than zinc plating, giving these bolts a thicker coating than other finishes.
- Tensile Strength: 120,000 psi
- Dimensional Standards: ASME B18.2.6
- Material Quality Standards: ASTM A325; ASTM F3125
A325 Types
| TYPE 1 | Medium carbon, carbon boron, or medium carbon alloy steel. |
|---|---|
| TYPE 2 | Withdrawn November 1991. |
| TYPE 3 | Weathering steel. |
| T | Fully threaded A325. (Restricted to 4 times the diameter in length) |
| M | Metric A325. |
A325 Hex bolt Connection Types
| SC | Slip critical connection. |
|---|---|
| N | Bearing type connection with threads included in the shear plane. |
| X | Bearing-type connection with threads excluded from the shear plane. |
A325 Mechanical Properties
| Size | Tensile, ksi | Yield, ksi | Elong. %, min | RA %, min |
|---|---|---|---|---|
| 1⁄2 – 1 | 120 min | 92 min | 14 | 35 |
| 11⁄8 – 11⁄2 | 105 min | 81 min | 14 | 35 |
A325 Type 1 Hex bolt Chemical Properties
| Heat Analysis | 120ksi, % | 150ksi, % |
|---|---|---|
| Carbon | 0.30 – 0.52 | 0.30 – 0.48* |
| Manganese | 0.60 min | 0.60 min |
| Phosphorus | 0.035 max | 0.035 max |
| Sulfur | 0.040 max | 0.040 max |
| Silicon | 0.15 – 0.30 | – |
| Boron | 0.003 max | 0.003 max |
| Copper | – | – |
| Nickel | – | – |
| Chromium | – | – |
| Molybdenum | – | – |
| *Carbon 0.35-0.53% for 1-1/2” A490/150ksi bolts |
A325 Type 3 Chemical Properties
| Heat Analysis | 120ksi, % Comp A | 120ksi, % Comp B | 120ksi, % Index | 150ksi, % Index |
|---|---|---|---|---|
| Carbon | 0.33 – 0.40 | 0.38 – 0.48 | 0.30 – 0.52 | 0.30 – 0.53 |
| Manganese | 0.90 – 1.20 | 0.70 – 0.90 | 0.60 min | 0.60 min |
| Phosphorus | 0.035 max | 0.035 max | 0.035 max | 0.035 max |
| Sulfur | 0.040 max | 0.040 max | 0.040 max | 0.040 max |
| Silicon | 0.15 – 0.30 | 0.30 – 0.50 | ||
| Copper | 0.25 – 0.45 | 0.20 – 0.40 | 0.20 – 0.60 | 0.20 – 0.60 |
| Nickel | 0.25 – 0.45 | 0.50 – 0.80 | 0.20 min* | 0.20 min* |
| Chromium | 0.45 – 0.65 | 0.50 – 0.80 | 0.20 min | 0.20 min |
| Molybdenum | 0.06 max | 0.10 min* | 0.10 min* | |
| *Either Nickel or Molybdenum must be present in the amount specified *Corrosion Index based on ASTM Guide G101 |
A325 Recommended Hardware
| Nuts | Washers | |||
|---|---|---|---|---|
| Type 1 | Type 3 | Type 1 | Type 3 | |
| Plain | Galvanized | Plain | ||
| A563C, C3, D, DH, DH3 | A563DH | A563C3, DH3 | F436-1 | F436-3 |
A325 Type 1 bolts are made to a specific configuration, including a heavy hex head and a flat bearing surface under the head. The bolts are hot-dip galvanized to provide corrosion resistance and have a minimum zinc coating thickness of 1.0 mil (25 microns).
A325 Type 1 bolts are commonly used in structural steel applications such as bridges, buildings, and towers. It’s important to ensure that the bolts are installed and torqued correctly to ensure optimal performance and safety in the application.
| Surface Finishing | Zn- Plated,Ni-plated,Passivated,Tin-plated,Sandblast and Anodize, Chromate, Polish,Electro Painting,Black Anodize,Plain,Chrome plated, Hot Deep Galvanized(H. D. G. ) etc. |