Fiberglass Threaded Rods Explained: Sizes, Strength, and Industrial Uses

Common Sizes of Fiberglass Threaded Rod (With Inch-to-mm Conversion)

Fiberglass threaded rods come in a variety of diameters and thread pitches, commonly in imperial units but often adapted for global use. Below is a size reference for standard options, with approximate metric conversions:

Threaded rods are typically available in 36" (914 mm), 48" (1219 mm), or custom-cut lengths. Metric threads like M8, M10, and M12 are also produced based on demand.

Key Differences: Threaded Rod vs Standard FRP Rod

While both are made of fiberglass reinforced plastic (FRP), threaded fiberglass rods serve different mechanical and functional purposes than smooth FRP bars:

The threads are molded or machined into the rod, allowing for nuts, washers, and mechanical connections—a feature not possible with standard composite rods.

Typical Use Cases and Installation Benefits

Due to their electrical insulation, corrosion resistance, and non-magnetic properties, threaded fiberglass rods are essential in:

• Electrical Cabinets & Power Systems
  Used to mount components inside high-voltage environments, where metallic fasteners pose safety risks.

• Marine and Offshore Equipment
  Ideal for saltwater exposure without rust or degradation.

• Chemical Plants and Cleanrooms
  Compatible with aggressive chemicals and non-conductive environments.

• Bridge and Tunneling Infrastructure
  Lightweight yet strong for anchoring and structural fastening in confined spaces.

Mechanical Performance: Tensile Strength & Durability

The tensile strength of fiberglass threaded rods depends on diameter and resin type. Standard values include:

• 1/4" Rod: Approx. 100 MPa

• 1/2" Rod: Up to 200 MPa

• 1" Rod: 250–300 MPa (depending on composition)

These values can be enhanced with epoxy or vinyl ester resins, which also improve temperature resistance and long-term creep performance.