This order came from a long-standing American customer with whom we’ve collaborated over ten times. We’ve maintained close contact, and the ASTM A325 bolts in this order are one of our flagship products. Therefore, we quickly provided a quote, and after finalizing the product details, the customer quickly placed the order.
ZIZI specialize in selling all kinds of stainless steel pipe fittings, tubes, plates, flanges, bolts and nuts, our products are widely used in many fields, from precision machinery manufacturing to warm home decoration and even high-end aerospace industry. We have become a trusted choice for many industries due to our superior product quality and wide range of applications. Not only do we offer a wide range of products, but we can also provide customized processing services according to the specific needs of our customers, ensuring that your expectations are accurately met every time we work together. With advanced production equipment and strict quality management system, we are committed to providing high-quality piping solutions to customers worldwide. Welcome to contact us.
Products Lists
| No | Description of Goods | Quantity | Units |
| 1 | BOLT, HEAVY HEX, 3/8″ UNC x 1 1/2″ LG, ASTM F3125 GR. A325 TYPE 1, HOT DIPPED GALVANISED | 90 | EA |
| 2 | BOLT, HEAVY HEX, 3/8″ UNC x 1 1/4″ LG, ASTM F3125 GR. A325 TYPE 1, HOT DIPPED GALVANISED | 20 | EA |
| 3 | BOLT, HEAVY HEX, 3/8″ UNC x 2″ LG, ASTM F3125 GR. A325 TYPE 1, HOT DIPPED GALVANISED | 60 | EA |
| 4 | BOLT, HEAVY HEX, 3/8″ UNC x 3/4″ LG, ASTM F3125 GR. A325 TYPE 1, HOT DIPPED GALVANISED | 20 | EA |
Inspection of ASTM A325 Bolts
Surface defects: Inspect the bolt surface for cracks, burrs, scratches, rust, or peeling of the coating. These defects can affect the bolt’s strength and corrosion resistance.
Head Markings: Inspect the bolt head to ensure that manufacturer information and strength grade are clearly and completely marked. This is a critical basis for assessing bolt quality and performance.
Thread Integrity: Inspect the threads for damage, defects, or deformation to ensure smooth nut engagement.
Length: Use calipers or a micrometer to measure the effective length of the bolt to ensure it meets design requirements.
Thread tolerance: Use a thread gauge to check the precision and tolerance of the threads to ensure proper fit with the nut.
Head dimensions: Measure the diagonal dimensions and height of the bolt head to ensure the wrench can apply force correctly.
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. |
Connection type of ASTM A325 Bolts
| SC | Slip critical connection. |
| X | Bearing-type connection with threads excluded from the shear plane. |
| N | Bearing type connection with threads included in the shear plane. |
ASTM A325 Bolt Chemical Composition
| Type 1 Bolts | ||||
| Element | Carbon Steel | Carbon Boron Steel | Alloy Steel | Alloy Boron Steel |
| Carbon | 0.30 – 0.52% | 0.30 – 0.52% | 0.30 – 0.52% | 0.30 – 0.52% |
| Manganese, min | 0.60% | 0.60% | 0.60% | 0.60% |
| Phosphorus, max | 0.04% | 0.04% | 0.04% | 0.04% |
| Sulfur, max | 0.05% | 0.05% | 0.04% | 0.04% |
| Silicon | 0.15-0.30% | 0.10 – 0.30% | 0.15 – 0.35% | 0.15 – 0.35% |
| Boron | 0.0005 – 0.003% | 0.0005 – 0.003% | ||
| Alloying Elements | * | * | ||
ASTM A325 Bolt 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 |
Features
High strength: Depending on the bolt diameter, the minimum tensile strength can reach 120 ksi (for bolts with a diameter ≤ 1 inch) or 105 ksi (for bolts with a diameter > 1 inch to 1.5 inches). This enables A325 bolts to withstand significant tensile and shear loads.
Heavy-duty hex head: A325 bolts feature a heavy-duty hex head design, with a larger and thicker head compared to standard hex bolts. This design provides a larger bearing area, effectively distributing clamping force across the connected steel components.
Short thread length: Unlike standard bolts, the threaded portion of A325 bolts is typically shorter. This is to ensure that in shear connections, the bolt’s shank (non-threaded portion) can better withstand shear forces, as the threaded portion is the weak point of the bolt.
Matching components: A325 bolts must be used with nuts (such as ASTM A563) and washers (such as ASTM F436) that meet specific standards to ensure consistent performance of the entire connection system.
ASTM A325 Bolt Dimensions
| Bolt Diameter | D | F | C | H | T | |||||
| Body Diameter | Width Across Flats | Width Across Corners | Height | Thread Length | ||||||
| Max | Basic | Max | Min | Max | Min | Basic | Max | Min | Basic | |
| 1⁄2 | 0.515 | 7⁄8 | 0.875 | 0.85 | 1.01 | 0.969 | 5⁄16 | 0.323 | 0.302 | 1 |
| 5⁄8 | 0.642 | 11⁄16 | 1.062 | 1.031 | 1.227 | 1.175 | 25⁄64 | 0.403 | 0.378 | 1.25 |
| 3⁄4 | 0.768 | 11⁄4 | 1.25 | 1.212 | 1.443 | 1.383 | 15⁄32 | 0.483 | 0.455 | 1.38 |
| 7⁄8 | 0.895 | 17⁄16 | 1.438 | 1.394 | 1.66 | 1.589 | 35⁄64 | 0.563 | 0.531 | 1.5 |
| 1 | 1.022 | 15⁄8 | 1.625 | 1.575 | 1.876 | 1.796 | 39⁄64 | 0.627 | 0.591 | 1.75 |
| 11⁄8 | 1.149 | 113⁄16 | 1.812 | 1.756 | 2.093 | 2.002 | 11⁄16 | 0.718 | 0.658 | 2 |
| 11⁄4 | 1.277 | 2 | 2 | 1.938 | 2.309 | 2.209 | 25⁄32 | 0.813 | 0.749 | 2 |
| 13⁄8 | 1.404 | 23⁄16 | 2.188 | 2.119 | 2.526 | 2.416 | 27⁄32 | 0.878 | 0.81 | 2.25 |
| 11⁄2 | 1.531 | 23⁄8 | 2.375 | 2.3 | 2.742 | 2.622 | 15⁄16 | 0.974 | 0.902 | 2.25 |
Installation and Maintenance
Installation Requirements: Before installation, inspect the bolts to ensure their specifications and performance meet design requirements. Ensure the bolt surfaces are clean and free of oil, rust, or other defects. During installation, tighten the bolts according to the specified torque. For shear-type bolts, ensure that the shear condition of the shear slot meets the requirements to ensure that the preload meets the design standards. Additionally, avoid over-tightening the bolts during installation to prevent plastic deformation or breakage.
Maintenance and Inspection: During use, bolts should be inspected regularly to check for loosening, rust, cracks, or other issues. Loose bolts should be tightened promptly. Bolts with severe rust or cracks should be replaced immediately to prevent compromising the safety of the connection structure. Additionally, bolts used in humid or corrosive environments should be protected with measures such as regular application of anti-rust paint to extend their service life.