Railway Wooden Sleeper Screws | Track Fasteners Manufacturer

Railway sleeper screws for wooden ties, also known as coach screws or lag screws, are heavy-duty threaded fasteners designed to provide strong, durable fixation of the rail or baseplate to the timber sleeper. Their design emphasizes high pull-out resistance and ease of installation directly into the wood. 

Key Features and Design

• Head Type: Typically feature a hexagonal or square head to allow for high torque application using a wrench, socket, or impact driver. Some modern timber screws also use a Torx drive for enhanced grip and reduced cam-out.

• Thread Design: They have a deep, coarse single-thread design with a sharp point, often a gimlet or type 17 slash point, which facilitates quick penetration into the wood and often eliminates the need for pre-drilling (in most timbers) to prevent the wood from splitting.

• Collar: A round collar or flange head design is common, acting as a built-in washer to distribute the load evenly and prevent the screw head from sinking too deeply into the wood.

• Installation: Unlike cut spikes which are driven in, these screws are threaded into a pre-bored pilot hole (for larger diameters or very dense wood) or directly into the wood, which provides a much stronger hold and makes removal easier for maintenance. 

Materials and Corrosion Resistance

Sleeper screws for wooden ties are typically made from high-strength carbon or alloy steel and require robust coatings to withstand outdoor exposure. 

• Material: Common materials include Q235, 35#, or 45# carbon steel, with high-strength alloy steel used for more demanding applications.

• Corrosion Protection: Given outdoor exposure, they come with various finishes to resist rust:

• Hot-dip galvanization (HDG): Provides excellent, long-term corrosion resistance for wet or coastal environments.

• Dacromet/Ruspert Coating: Offers very high, long-lasting resistance, often tested to withstand 1000+ hours of salt spray.

• Stainless Steel: Grades like A2 or A4 (316 marine-grade) offer superior inherent corrosion resistance, ideal for highly corrosive or coastal sites.

• Plain oiled or black oxide finishes are also available but offer less protection. 

Common Types and Standards

These fasteners adhere to standards UIC864-1, AREMA, and DIN. 

Kunshan Signum Machinery Technology Co.,Ltd is able to customize railway sleeper screws according to your specific requirements and with competitive price. If you need them, please feel free to contact us.