FRP bolting kits contain non-metallic threaded rods, nuts, and washers made from pultruded or molded FRP material, allowing a fully non-conductive, corrosion-proof connection between FRP profiles. These kits remove the last metal component from the assembly, which matters in electrical substations and MRI facility enclosures where even a stainless bolt introduces a conductive path.
A fiberglass bolting kit is specified when the entire structural assembly must remain electrically inert. In a switchyard or a transformer plinth, a metal bolt creates a potential difference across the grating panel—exactly the condition that safety engineers work to eliminate. An FRP threaded rod, tightened with FRP nuts and seated against FRP washers, breaks that circuit entirely. The dielectric strength of the pultruded rod exceeds 20 kV/mm, so even during a ground‑fault event, there is no conductive route through the fastener to the supporting steel below.
On the corrosion side, an FRP fastener kit provides the same chemical resistance as the FRP grating panels it secures. The vinyl ester or polyester resin matrix in the threaded rod is immune to the same acids, alkalis, and salt spray that the grating itself is designed to withstand. For non‑metallic grating bolts in a chlorine storage building or a coastal wastewater plant, there is no coating to scratch, no galvanic couple to drive, and no difference in thermal expansion between the fastener and the panel. The result is a connection that stays tight and electrically safe for the full design life of the grating system.
Kit Contents & Specifications
| Kit contents | 1 threaded rod, 2 nuts, 2 flat washers — all FRP |
|---|---|
| Threaded rod material | Pultruded FRP, vinyl ester or polyester matrix with glass reinforcement |
| Rod diameters | M8, M10, M12 (5/16″, 3/8″, 1/2″) |
| Rod lengths | 50–150 mm (2–6 in), depending on grating depth and connection detail |
| Tensile strength | ≥ 400 MPa (58 ksi) longitudinal (ASTM D638) |
| Dielectric strength | > 20 kV/mm (ASTM D149) |
| Resin system | Vinyl ester (standard); isophthalic polyester available for less aggressive environments |
| Corrosion resistance | Immune to chloride, acid, and alkali attack; pH range 1–14 (vinyl ester) |
| Fire rating | Flame spread index ≤ 25 (ASTM E‑84) |
Each kit is individually bagged and labelled with rod diameter and length for quick distribution on site. Installation uses a standard torque wrench set to 8–12 N·m—the FRP threads require a lighter hand than steel, and the torque range is calibrated to achieve full clamping force without galling the resin threads. These fasteners complete the accessories and hardware package alongside stainless steel clips and carbon steel clamps, giving the specifier a single source for every grating fastener across the full spectrum from indoor dry to offshore splash zone. For guidance on where non‑metallic fasteners are mandatory, see the cable management systems section covering electrical safety in substation grating layouts.
Proven in Field
“The substation grating retrofit required every fastener to be non‑conductive—no exceptions. We used FRP bolting kits throughout, over 800 connections. Post‑installation ground‑fault testing confirmed zero stray current paths through the grating, and the fasteners show no measurable degradation after three years of outdoor exposure adjacent to live 132 kV equipment.”
— Excerpt from Substation Grating Electrical Safety Upgrade