HSFG / STRUCTURE BOLTS – ASTM A325M

🔩 High-Strength Friction Grip Bolts for Structural Steel Connections

ASTM A325M HSFG (High Strength Friction Grip) Bolts are heavy-duty, high-tensile structural bolts designed for critical steel-to-steel connections in construction and infrastructure projects. These bolts are engineered to create friction-based joints under high preload, ensuring long-term stability, strength, and resistance to shear and vibration.

At National Fasteners, we supply precision-manufactured ASTM A325M structural bolts in metric dimensions, ideal for steel bridges, high-rise buildings, towers, and industrial structures where joint integrity is non-negotiable.

🔧 Product Specifications:

• Standard: ASTM A325M

• Size Range: M16 to M36 (2″ TO 4″ INCH)

• Thread Type: Metric Coarse (partial thread)

• Property Class: 8S, 10S, 8.8

• Head Type: Heavy Hex Head

• Shank Type: Plain or short-threaded (minimum thread)

• Surface Finishes:

  • Hot-Dip Galvanized

  • Zinc Plated

  • Phosphate Coated

  • Black Oxide

  • Self-Color (Plain)

• Available Sets:

  • Bolt + Nut (ASTM A563M / A194)

  • Bolt + Nut + Washer (F436 or Equivalent)

⚙️ Key Features of ASTM A325M HSFG Bolts:

• Designed for preloaded structural joints using tension control

• Provides superior clamping force and shear resistance

• Heavy hex head offers higher bearing area

• Complies with international structural codes and standards

• Available with compatible nuts and washers for full assembly

• Suitable for both slip-critical and bearing-type connections

🏗️ Common Applications:

• Steel bridges and flyovers

• High-rise buildings and industrial towers

• Transmission towers and wind turbine bases

• Structural frameworks for plants and factories

• Offshore and port infrastructure

• Pre-engineered building (PEB) systems

💡 Why Choose National Fasteners for HSFG Bolts (ASTM A325M)?

✅ ISO 9001:2015 Certified Manufacturing Facility
🧪 100% In-House Quality Testing – Hardness, Tensile, Magnetic Particle
⚙️ Matched Bolt-Nut-Washer Assemblies Available
🏭 High-Volume Production with Fast Turnaround
🌍 Global Supply Network – Trusted by EPCs, OEMs & Fabricators

📞 Request a Quote or Sample

Need certified HSFG / Structural Bolts (ASTM A325M) for your steel connection project?
Reach out today for technical support, pricing, and bulk delivery.

👉 Request a Quote | 📧 sales@nationalfasteners.in | 📞 +91 70093-08799