GRP flat bar is the simplest section we pultrude and the one that turns up in the most places: a rectangular strip of glass-reinforced plastic, constant along its length, that gets bolted, bonded, drilled and cut into whatever the job needs. NA-ME makes it in two quite different groups. The narrow group runs from 20 to 100 mm wide and behaves like a bar. The wide group runs from 500 to 850 mm and behaves like a panel. They do different work, and buying the wrong one is the commonest mistake on this product.
Both groups come off the same process and carry the same CPF family letter, but that is where the similarity stops.
Flat bar — 20 to 100 mm wide. This is a linear component. You use it as a connection plate between two members, as a backing strap behind a bolted joint, as edge trim on a cut sheet, as a grating hold-down, as a reinforcing strip on a panel edge, or as a spacer that has to be non-conductive. It is bought by the metre and cut to short lengths on site. Thicknesses run from 2 to 12 mm.
Wide flat section — 500 to 850 mm. This is a surface. At these widths the profile is doing the job of a plate: a walking surface, a cover, a lining, a cladding panel, a deck over a trench. It is bought as sheet-like stock, handled by two people rather than one, and it is a different order of magnitude in both cost and weight. A 850 × 8 mm section weighs 12.30 kg/m; a 20 × 5 mm flat bar weighs 0.18 kg/m.
If you are sizing a bolted connection, you want the first table. If you are covering an opening or building a walking surface, you want the second. The same product appears in specifications as FRP flat bar, fiberglass flat bar, GRP strip or GFK flat — for a glass-fibre profile they all describe this section.
| Code | Width (mm) | Thickness t (mm) | Weight (kg/m) |
|---|---|---|---|
| CPF-O-101 | 20 | 5 | 0.18 |
| CPF-O-102 | 25 | 5 | 0.23 |
| CPF-O-103 | 30 | 5 | 0.28 |
| CPF-O-104 | 40 | 6 | 0.42 |
| CPF-O-105 | 50 | 6 | 0.55 |
| CPF-O-106 | 60 | 10 | 1.11 |
| CPF-O-107 | 75 | 10 | 1.37 |
| CPF-O-108 | 80 | 8 | 1.20 |
| CPF-O-109 | 95 | 2 | 0.32 |
| CPF-O-110 | 100 | 10 | 1.84 |
| CPF-O-111 | 100 | 12 | 2.62 |
| Code | Width (mm) | Thickness t (mm) | Weight (kg/m) |
|---|---|---|---|
| CPF-O-112 | 500 | 10 | 9.02 |
| CPF-O-113 | 610 | 3 | 3.30 |
| CPF-O-114 | 610 | 6 | 8.54 |
| CPF-O-115 | 610 | 8 | 11.39 |
| CPF-O-116 | 610 | 12.7 | 14.33 |
| CPF-O-117 | 850 | 4 | 6.64 |
| CPF-O-118 | 850 | 6 | 10.50 |
| CPF-O-119 | 850 | 8 | 12.30 |
Weights are per metre for the orthophthalic grade. The section number is tied to the geometry, so the same number in a different resin has identical dimensions and identical weight.
Between 100 and 500 mm there is a gap in the standard programme. That is not a limitation of the process; it is simply where the standing dies happen to sit. NA-ME cuts its own dies, so an intermediate width is a question of quantity and lead time. Send the width and thickness you actually want.
Every profile carries a three-part code. Take CPF-O-110:
Practically, this means you settle the size first and the resin second, and neither decision constrains the other.
The glass carries the load; the resin decides how long the profile survives its surroundings. We pultrude flat sections in six systems.
These are separate codes in our production list rather than a coating applied afterwards. The full comparison, and what each system genuinely resists, is on resin systems. Outdoors, the surface veil is what protects the resin from UV and stops the fibre pattern showing through after a few seasons; see surface veil, UV and fire.
Because GRP is not welded, every joint is mechanical. A flat bar behind a bolted joint spreads the bearing load over a wider area of the member, which is exactly what a low-modulus material needs at a bolt hole.
Strips that clamp grating panels down, close off a cut edge, or finish the perimeter of an opening. Non-conductive and corrosion-free, so the trim outlasts the fixings.
Bonded or bolted along a panel edge or across a span to add local stiffness without adding a second structural member.
Where two metal parts must not be in electrical contact, a flat GRP strip separates them and takes the compression without corroding at the interface.
At 500 mm and above the section is a surface, and the applications change accordingly: walkway and platform decking where a solid surface is wanted instead of open grating, covers over trenches and channels, machine guarding panels, lining and cladding on structures that cannot be repainted, and bases or wear surfaces in wet or chemically loaded areas. The thin end of the range — 610 × 3 mm at 3.30 kg/m — is a cladding and facing material. The thick end, 610 × 12.7 mm, is a structural deck.
One point deserves emphasis for the wide group. GRP is a directional material: strong along the direction of the pull, considerably weaker across it. A wide pultruded section is stiff along its length and comparatively flexible across its width, so it must be supported along the direction it is spanning, not treated as an isotropic plate. Get the support spacing right and it performs; treat it as steel plate and it will deflect more than you expected.
GRP has a low to medium modulus of elasticity. On almost every span that means the section is chosen to satisfy a deflection limit, and the strength margin that comes with it is generous. It weighs roughly a quarter of what steel does, does not rust or rot, is electrically non-conductive, has low thermal conductivity, and stands up to UV, weather and chemical attack. Where the numbers matter for a calculation, they are on mechanical properties. How a section is actually made, and why that makes it repeatable, is on the pultrusion process.
NA-ME holds ISO 9001, ISO 14001 and ISO 45001 certification covering the design and manufacture of composite products. We explain the standards above because buyers write them into tenders; we do not claim them as certifications we hold. What we test in house is set out on quality, standards and testing.
For a solid circular section — pins, dowels, connectors — see GRP rod. For hollow circular sections, posts and handrails, see GRP round tube. Where a flat bar is being used as corner reinforcement, an FRP angle is often the better answer. The complete range is listed on GRP and FRP structural shapes, and applications by industry shows where each section tends to end up. Fixing detail — bolt spacing, edge distance, hole preparation — is on installation and fastening.
Give us the width, the thickness, the length and the quantity, and say in a sentence what the environment is: indoor, outdoor, coastal, chemical, fire clause. That is enough to confirm a section from the tables or to tell you what a new die would take. We have pultruded in Ankara since 1982, around half our output is exported, and EU destinations are 3 to 7 days from the plant by road with no customs duty on industrial goods under the EU–Turkey Customs Union. Mixed and small orders are normal here.