Custom Non-Standard Flange Bolts, Preferred Choice for Grain Silo Fastening

Case Analysis

In grain storage industry, this assembled flange bolt with EPDM washer is widely used fastener for grain silos. Compared with ordinary bolts, this silo bolt can effectively distribute load and provide reliable waterproof sealing. For grain bin projects, standard bolts may fail to fully meet special application requirements, in which case this silo flange bolt becomes an important solution.

Standard Bolts VS Grain Silo Flange Bolts

1. Background & Requirements for Grain Silo Flange Bolts

For a large grain silo project, common standard bolts could not satisfy the following requirements:

• High strength requirement: The silo bears static load and wind vibration, demanding higher tensile strength and fatigue resistance of the bolts.
• Waterproof & corrosion resistance: Grain silos are exposed to humid atmosphere, dew and dust all year round. The bolt needs good sealing performance and anti-rust ability.
• Matching assembly: Pre-assembled combination of hex flange nut, metal washer and EPDM rubber washer, ready for quick installation on silo steel sheets.

2. Custom Design of Grain Silo Flange Bolts

2.1 Material Selection

Based on project requirements, carbon steel is selected with zinc plating surface treatment.

• High strength: Proper heat treatment meets required tensile strength for silo structure.
• Corrosion resistance: Zinc plating forms a protective layer to resist rust in humid warehouse environment.

2.2 Structural Design Optimization

The design focus of silo flange bolt lies on pre-assembled washers:

• Pre-attached EPDM sealing washer: Black rubber gasket provides waterproof sealing to stop water infiltration at connection points.
• Metal backup washer: Reinforces pressure bearing, prevents rubber gasket from being crushed during tightening.
• Full thread design: Continuous thread along shank, flexible for different silo sheet thickness.

2.3 Surface Treatment Process

To meet humid grain storage environment:

• Zinc electroplating: Forms uniform zinc coating, improves rust resistance for grain bin outdoor & indoor service.

3. Production Process

1. Raw Material Preparation High-quality steel bars are selected, cut for heading to ensure dimensional consistency.
2. Heading Forming Cold forging to form hex head in one step, stable structure.
3. Thread Machining Thread rolling process is used instead of cutting to avoid stress concentration and improve thread strength and durability.
4. Heat Treatment Heat treatment to achieve required mechanical strength.
5. Assembly Pre-assemble metal washer + EPDM rubber washer on bolt, one-piece ready-to-use fastener.
6. Quality Inspection Dimensional measurement, tensile test and salt spray test are carried out to ensure all bolts meet silo project specifications.

4. Application Scenarios & Field Performance

This silo flange bolt is specially designed for grain storage facilities：

• Steel grain silos: For connecting corrugated silo sheets, stable fastening under wind load and vibration.
• Farm grain bins: Waterproof sealing prevents moisture ingress to protect stored grain.
• Grain storage auxiliary frames: Reliable connection for silo supporting structures.

Field advantages:

• Stable & sealed connection: Pre-assembled EPDM gasket keeps water out, maintains tight fastening under wind vibration.
• Good rust resistance: Zinc plated surface withstands humidity and condensation in grain storage environment.
• Fast installation: All washers pre-assembled, saves on-site assembly time and reduces labor cost.

5. Value & Prospect of Grain Silo Flange Bolts

For grain silo construction projects, this pre-assembled flange bolt outperforms ordinary standard bolts. Optimized assembly structure and coating satisfy the special sealing and strength requirements of grain bins.

If your grain silo project needs this kind of pre-assembled flange bolt with rubber washer, we can supply reliable fastening solutions. We provide professional manufacturing service, support bulk supply for grain storage projects!