Belt Screw

Belt Screw — Product Introduction

The belt screw is a specialized fastener conforming to the DIN 15237-1980 standard, primarily used to securely attach elevator buckets, scoops, and similar components to conveyor belts or drive belts. Its head features a countersunk or concave design with a square neck or sharp claws beneath, used together with cup washers and nuts. The anti-rotation and anti-loosening design ensures reliable connection under continuous vibration conditions.

I. Product Features

• Countersunk and anti-rotation structure: The bolt head features a countersunk or concave design with a square neck or two pointed claw projections beneath. During installation, the square neck or claws embed into pre-punched holes in the belt; when the nut is tightened, the bolt does not rotate, allowing one-sided operation.
• Cup washer as standard companion: The standard specifies use with cup-shaped (bowl-type) washers; the curved surface of the washer contacts the belt surface, distributing pressure evenly over a larger area to prevent local crushing or tearing of the belt.
• Diverse materials and specifications: Common materials include carbon steel (zinc-plated/blackened) and stainless steel (304/316). Thread sizes cover M6 to M12, with head diameters ranging from approximately 21mm for M6 to approximately 42mm for M12. Common property classes are 4.6, 5.8, and 8.8; stainless steel versions are typically A2-70.
• Full thread or partial thread options: Depending on assembly requirements, full-thread or partial-thread versions are available; full threads facilitate adjustment, while partial threads perform better under shear loads.
• Flexible installation direction: Typically inserted from beneath the belt; the threaded shank passes through the pre-punched hole, the bucket is then fitted, and the nut and washer are used to secure the assembly.

II. Product Advantages

• Anti-loosening and vibration-resistant: The mechanical interlock between claws or square neck and the belt hole, combined with the elastic clamping of the cup washer, effectively resists continuous vibration during elevator operation, preventing bolt loosening or detachment.
• Belt protection and extended service life: The large contact area of the cup washer prevents the bolt head from directly cutting into or crushing the belt, while the countersunk structure ensures the bolt head does not scratch the roller rubber surface when passing around pulleys.
• Efficient installation and precise positioning: The claw design allows preliminary positioning before tightening, reducing displacement during installation; one-sided operation is sufficient, making it suitable for confined spaces.
• Wear-resistant and adaptable to harsh conditions: Carbon steel zinc-plated versions offer good rust resistance; stainless steel versions are suitable for humid, dusty, and mildly corrosive environments, ideal for agricultural and grain processing applications.
• Standardized with good interchangeability: Conforming to DIN 15237, dimensions are unified and products from different suppliers are interchangeable, facilitating maintenance and spare parts management.

III. Application Scope

• Bucket elevators: In vertical conveying systems for bulk materials such as grain, feed, fertilizers, and ore, used to secure buckets to elevator belts — the most important application.
• Conveyor belt systems: Various conveyor and belt conveyor applications where attachments, baffles, or buckets need to be secured to the belt surface.
• Agriculture and grain processing: Connections between buckets and belts in grain elevators, seed processing lines, and feed production lines.
• Industrial material handling: Reliable belt-to-component fastening in continuous mechanical handling equipment in cement, chemical, and mining industries.
• Vehicle floors and lifting equipment: Vehicle floor attachment, lifting equipment component connections, and other applications requiring countersunk, scratch-resistant, and high anti-loosening performance.