Filament Wound Tube Suppliers: How to Shortlist and What to Ask
Sourcing & Suppliers · 2026-09-16 · 5 min read
Filament winding sits in an awkward category for a buyer. The process is used for rocket motor cases, drive shafts and hydrogen vessels, and it is also used for a 30 mm insulating tube that goes into a breaker. Those are different suppliers with different minimum orders and different ideas about what a small batch is. The list below covers the range, and the questions after it sort them by whether they will wind to your load case or only sell you a stock tube.
Ten names to research
| Supplier | Based in | What they are known for in this category |
|---|---|---|
| WELLELE (Well Electric) | Suzhou, China | Thin-wall filament wound epoxy fiberglass tube for switchgear, breaker, fuse, medical and cryogenic insulation: close ID and OD, controlled concentricity, machined and deburred ends, small and mixed batches |
| Norplex-Micarta | Postville, USA | Thermoset composites across prepreg and filament wound tube, with a long history of tube supply to high-voltage electrical and aerospace duty; also operates a laminating plant in Jiangsu, China |
| Amalga Composites | USA | Filament wound composite tubing and machined components, oriented to custom engineering across industrial and energy applications |
| Goodwinds Composites | Mount Vernon, USA | Custom filament wound epoxy tubing in small diameters, used for probe housings, antennas and structural members where electrical and thermal insulation matter |
| Parker Hannifin | Cleveland, USA | Composite and engineered materials divisions supplying wound tube into aerospace, fluid systems and industrial OEM manufacturing |
| The Gund Company | USA | Electrical insulation materials and fabrication for power systems, including tube and machined insulation for transformer and switchgear OEMs |
| Franklin Fibre-Lamitex | USA | Industrial laminates, vulcanized fibre and filament wound epoxy composite tube, with custom engineering for chemical processing and medical equipment |
| Current Inc. | USA | Laminated plastics and electrical-grade tubing, oriented to cost-effective thin-wall sections in epoxy and phenolic grades |
| Spaulding Composites | USA | Specialty composites for extreme environments, with an emphasis on wear-resistant formulations and heavy industrial duty |
| Hexagon Composites | Norway | Large filament winding group at the structural and pressure-vessel end of the process, mainly energy and transport applications |
One more name worth knowing where the application is aerospace or defence structural tubing is Kineco Group in India, which winds composite structures under aerospace quality systems. The point of including it is that the supplier list for filament winding is far wider than the supplier list for filament wound insulation tube, and most of those companies will not quote a 200-piece batch of 25 mm tube.
Five questions that sort the list
- Do you set the winding angle from my load case, or is the tube a stock winding? This is the question that separates a winder from a distributor. A winder will ask for the pressure or the column load before quoting.
- What is the minimum wall you will commit to at my bore? A wall figure without a diameter attached means nothing, and a supplier who quotes one has not thought about the process.
- How do you hold concentricity, and what is the figure? The bore comes from the mandrel and the outside diameter should be machined from the bore. If the answer is that the outside diameter is ground from the outside in, expect a variable wall.
- How do you machine the ends, and how do you avoid delamination? Sharp tooling on a change schedule, bore support and a controlled depth of cut at the free edge are the answers you want.
- What is your minimum order, and how long is the run? Filament winding has real setup time, so a supplier whose minimum is 5,000 pieces is not the supplier for a 200-piece instrument build.
Where the market actually splits
| Buyer | Supplier type that fits | What they are really buying |
|---|---|---|
| Switchgear, breaker and interrupter OEM needing a thin insulating tube | Custom winder with small-batch capability | Close concentricity and a machined end interface, at a batch size that matches the build |
| Fuse OEM needing a structural insulating body | Custom winder or a laminate tube house | Controlled bore, dimensional consistency across lots, and documented material |
| Aerospace or defence structural tube | Aerospace-qualified composite house | Qualification paperwork as much as the tube |
| Pressure vessel or drive shaft | Structural filament winding group | Load-case engineering at high volume |
| Instrument or medical build needing a few hundred parts | Custom winder with small-batch capability | Availability and dimensional control, with no volume commitment |
How to run the shortlist
- Write the drawing with the bore, wall, tolerance, concentricity as a wall variation, the end machining and the environment.
- Send the load case with it, even if the load is small. A winder who knows the load will pick the angle; one who does not will wind evenly and waste wall.
- Ask three suppliers for a sample lot and section one part to look at the wall and the end face.
- Measure the wall at several points around the circumference rather than once.
- Ask each supplier what they would change on the drawing. A winder will argue about the tolerance band; a reseller will quote it.
Where it fits in the wider build: our thin-wall filament wound micro tube route gathers every part that goes into it.
Products for this job
These are the wound tubes we run, from thin-wall micro tube up to larger load cases. Sample and prototype quantities for Filament Wound Tube Suppliers are quoted before any tooling is committed.
Related reading
- Thin-Wall Filament Wound Tubes Below 0.5 mm
- Out-of-Round Tubes and End Delamination
- Filament Wound vs Pultruded Fiberglass Tube
- G10 vs FR-4 Epoxy Fiberglass
Common questions
Who makes filament wound epoxy tubes?
The supply base splits by application. Structural and pressure work is served by groups such as Hexagon Composites and aerospace-qualified composite houses. Insulation tube for electrical duty is served by laminate and composite houses such as Norplex-Micarta, The Gund Company, Franklin Fibre-Lamitex and Current Inc., by custom winders such as Amalga Composites and Goodwinds Composites, and by drawing-based manufacturers such as WELLELE.
Why do some suppliers refuse small batches?
Filament winding has real setup and mandrel cost, so the economics change below a certain volume. A supplier set up for pressure vessels will not quote a few hundred instrument tubes. Look for a custom winder whose normal batch is in your range rather than trying to convince a large house.
How do I tell a winder from a reseller?
Ask whether the winding angle is set from your load case. A winder will ask for the pressure or the column load and propose an angle. A reseller will quote a wall and a diameter and mention the standard winding.
What is the minimum order for a custom wound tube?
It varies widely. Custom winders regularly run hundreds or low thousands of pieces for instrument and switchgear work, while structural composite houses quote in much larger volumes. Tell the supplier your annual usage up front, so the answer is realistic.
What should I check on a sample lot?
Wall variation at several points around the circumference, bore and outside diameter, end-squareness, and a sectioned part showing the wall and the end faces for voids and separation. Those checks catch the defects that dimension-only inspection misses.
Does the winding angle matter for an insulating tube?
It matters for stiffness and for hoop strength. Where the tube carries pressure or acts as a structural insulator, the angle should follow the load. Where it is a cover, an even winding is fine and cheaper. State the load and let the supplier propose the angle.
Can I use a pultruded tube instead?
For a cover with a moderate wall and a loose tolerance, yes, and it will be cheaper. Pultruded tube gives ground on concentricity and on thin-wall capability. Use filament winding where concentricity, thin-wall section or burst strength is the requirement.
What does WELLELE supply?
Thin-wall filament wound epoxy fiberglass tube with wall capability from around 0.2 mm at micro diameters, close ID and OD, controlled concentricity, machined and deburred ends, and a service range typically minus 50 C to plus 130 C depending on grade. Small and mixed-size batches are normal. Send the drawing and the load case.
Specifying this part?
Send the drawing for a manufacturability review.