Connecting Bolt

1. Concept

A connecting bolt is a type of mechanical part with external threads, used to connect, fix, or join components in construction, mechanics, wood, or metal. It is one of the small but important accessories in assembly structures.

2. Structure

• Bolt Head: Comes in many shapes (flat head, round head, pan head, hexagonal head, bake/Phillips head) to suit each type of tightening tool.

• Bolt Body: Cylindrical shape, with external threads (coarse or fine threads).

• Bolt Point: Can be pointed (used for wood, plastic) or drill type (used for sheet metal, steel).

3. Manufacturing Materials

• Stainless steel (201, 304, 316, 410) → rust-resistant, durable, used for humid environments, outdoors, marine works.

• Zinc-plated / electroplated carbon steel → cheaper, used indoors or where there is less water contact.

• High-strength steel alloy → used in mechanics, steel structures, factories.

4. Classification by Application

• Wood Screw: Pointed head, coarse thread, firmly grips wood.

• Self-drilling Screw: Has a drill bit, penetrates through sheet steel, sheet metal without the need for pre-drilling.

• Roofing Screw: Has a rubber washer to prevent leakage, specifically used for roofing.

• Machine Screw: Used with nuts, applied in machinery.

• Decorative stainless steel screws: Shiny, used in interior design, architecture.

5. Advantages

• Easy to construct: no need for complex equipment.

• High durability: good load-bearing capacity, strong connection.

• Variety of sizes: from M3 to M20, length 10 mm – 300 mm.

• Reusable: can be removed and replaced when needed.

6. Applications

• Construction of factories, residential buildings, roofing.

• Installation of mechanical equipment, machinery.

• Production of wood furniture, decoration.

• Fixing components in steel structures.

• Outdoor applications: billboards, marine works, docks (if using stainless steel 316).