Hook Bolt for Railway Bridge | Direct Manufacturer

Railway bridge hook bolts (also known as bridge tie bolts) are structural fasteners used to clamp timber or steel sleepers to the top flange of steel bridge girders. Unlike standard bolts, they allow for a secure connection without drilling through the main bridge structure, maintaining its structural integrity.

Core Types and Designs

• Standard J-Bolt: A basic rod with a curved hook that grips the underside of the girder flange.

• Square-Shank Hook Bolt: Features a square section under the head that bites into the sleeper. This prevents the bolt from spinning, allowing a single worker to tighten it from the top.

• Quick-Set® Hook Bolt: A high-efficiency design that can be installed and adjusted entirely from the bridge deck, significantly reducing labor and improving safety. 

Key Specifications

• Material Grade: Typically high-tensile steel, often 55# or Grade 8.8.

• Corrosion Protection: Hot-Dip Galvanizing (HDG) is the standard finish to ensure a long service life in harsh outdoor environments.

• Size Range: Standard diameters are 3/4", 7/8", and 1". Lengths are custom-matched to the "grip" (the total thickness of the sleeper and the girder flange). 

Material Specifications

To survive high-stress environments, these bolts use heavy-duty materials and finishes: 

• Grades: They are often made from medium carbon or alloy steel, with tensile strengths ranging from 110,000 to 150,000 PSI.

• High-Strength Options: Common structural standards include ASTM A325 and ASTM A490 (often replaced by the unified ASTM F3125 spec), which provide the exceptional shear and tensile strength needed for dynamic bridge loads.