Elevetor Bucket Bolts

Product Description

Elevator bucket bolts are specialized fasteners designed to secure conveyor buckets to belt or chain systems in vertical lift elevators. Because these systems often transport abrasive or heavy bulk materials (like grain, sand, or minerals), the bolts are engineered to prevent loosening and minimize wear on the belt.

The most distinctive feature of a bucket bolt is its large, flat, thin head, which is designed to sit flush against the conveyor belt to prevent interference with the elevator's pulleys.

Common Types of Bucket Bolts

There are three primary designs used in industrial applications, categorized by how they grip the belt to prevent the bolt from spinning during installation.

1. No. 1 Norway Flat Head

The most widely used style. It features a large, completely flat head and a square neck.

• Function: The square neck pulls into the belt or the bucket mounting hole to lock the bolt in position.

• Best For: Standard rubber or PVC belts where a low profile is essential to avoid pulley wear.

2. Fang Type (No. 3)

Instead of a square neck, this bolt has two sharp "fangs" or teeth located on the underside of the head.

• Function: The fangs bite into the conveyor belt as the nut is tightened, providing superior resistance to spinning.

• Best For: Thicker or harder belts where a square neck might not seat deeply enough to prevent rotation.

3. Ribbed Neck (No. 2)

This bolt features longitudinal ribs along the shank just under the head.

• Function: The ribs create a high-friction fit within the mounting hole.

• Best For: Specifically designed for use with chain-link elevators or buckets with reinforced mounting holes.

Material Grades and Coatings

The choice of material depends entirely on the substance being moved:

• Carbon Steel (Grade 2): The standard for non-corrosive, general-purpose bulk handling. Usually zinc-plated for basic rust protection.

• Grade 5 / Grade 8 Steel: Used for high-capacity systems carrying very heavy loads (like ore or coal) where higher tensile and shear strength are required.

• 304/316 Stainless Steel: Critical for food-grade applications (grain, sugar) or highly corrosive environments (fertilizer plants) to prevent contamination and rust-jacking.

Key Technical Specifications

Installation Considerations

• Belt Protection: Always use leather or rubber washers between the bolt head and the belt if the material is particularly soft. This prevents the large head from cutting into the belt fibers.

• Torque: Over-tightening can "dish" the bucket or crush the belt carcass, while under-tightening leads to the fangs or square neck stripping the belt material.

• Recessing: In high-speed systems, the belt is often "countersunk" slightly so the bolt head sits truly sub-flush, ensuring zero contact with the pulley surface.