We 3D print carbon-fibre-reinforced parts across seven chopped-fibre CF grades in the UK — from PLA-CF jigs to PA6-CF and PPS-CF end-use components. Chopped-fibre FDM buys stiffness, dimensional stability and surface finish, not headline tensile strength. Send your part and our team returns an engineer-reviewed quote in 6 hours.
That second sentence matters. Carbon fibre is the most over-sold word in 3D printing, and the parts that disappoint are almost always bought on the wrong property. This page tells you what the fibre actually does, which of our seven grades fits your part, and when you shouldn't buy carbon fibre at all.
"James handled the 3D printing for a functional heat resistant component we needed in batch production. He helped dial in the prototype first with their design service, then produced the final batch with really consistent results. Super fast 3D print turnaround and great quality across all the 3D printed parts. Will 100% be coming back."
"We needed a sit-in F1-car for an exhibition to showcase our new racing game. 3D Printing Express took our CAD, optimised it for strength and weight as we had no idea how it all worked! Turned out beautifully. They colour matched the finish and was looking like the real deal. On show day the cockpit ran non-stop, adults and kids jumped in. Multiple visitors asked who built it."
"We ordered a batch of 100 PA-12 parts from 3D Printing Express and could not be happier. Every part arrived consistent, dimensionally accurate, and ready for use straight from the box. The PA-12 gave us the strength and stability we needed for functional testing, with minimal post-processing required. Delivery was on time, communication was excellent, and their QC clearly made a difference."
The carbon in a CF filament is chopped fibre — short strands compounded through the base polymer. When that filament is extruded, the fibres do four useful things.
It makes parts stiffer. Stiffness — resistance to bending and flex under load — is the property carbon fibre genuinely sells. Fiberon PA6-CF20 reaches a Young's modulus of 8,636 MPa, the stiffest material we print, around 2.5× plain PLA.
It makes parts hold their shape. Fibres constrain the polymer as it cools, so CF grades shrink less, warp less, and print flatter. They also creep less under sustained load — a clamped CF-nylon bracket relaxes far more slowly than its unfilled equivalent. For fixtures and jigs that must stay dimensionally true, this is often the real reason to specify CF.
It improves the surface. The matte, low-sheen CF finish hides layer lines and reads as a finished engineering component straight off the printer.
It does NOT make parts dramatically stronger. Tensile strength rises far less than stiffness does — and the layer bond is untouched. Chopped fibres align along the extrusion path; they do not bridge between layers. Z-direction strength remains the design limit on every CF part we print (PA6-CF: 115.3 MPa along the layer, 54.0 MPa across it). That's not a reason to avoid CF — it's a reason to orient the part so the load runs along the fibre, which is exactly what our team checks on every CF quote.
Most carbon-fibre disappointment comes from buying strength when the fibre sells stiffness. We'd rather tell you that here than have you learn it from a broken part.
The numbers, since "carbon fibre" alone tells you nothing: adding 8% recycled chopped carbon fibre to PETG lifts Young's modulus from 2,117 MPa to 3,710 MPa (+75%) while tensile strength moves only 50.8 → 59.8 MPa (+18%) — the fibre buys stiffness, not strength. At the top of our range, 20%-filled PA6-CF reaches 8,636 MPa. And PLA-CF, with 8% milled (shorter) fibre, measures 3,281 MPa against 3,427 MPa for plain PLA — no stiffness gain at all; that grade is bought for its matte finish and zero-warp printability, and we say so on its page. Base polymer, fibre length and fibre loading decide everything.
Source: Polymaker PolyLite/Fiberon Technical Data Sheets, ISO 527, injection-moulded specimens. Printed parts are direction-dependent and test below moulded values.
"Carbon fibre 3D printing" covers two different technologies, and quotes are not comparable between them.
Chopped fibre — what we run. Short carbon strands compounded into the filament (the Polymaker Fiberon family, 8–20% fibre by mass). Printed on standard FDM hardware with hardened tooling, priced like engineering FDM, available across seven base polymers. The fibre raises stiffness, dimensional stability and heat tolerance of the matrix; the part remains a reinforced thermoplastic, not a composite laminate.
Continuous fibre — what we don't. Systems in the Markforged class lay an unbroken carbon strand inside the part along a programmed path. Along that path, tensile strength climbs toward metal-replacement territory — genuinely beyond anything chopped fibre can do. The trade: dedicated hardware, a substantially higher cost per part, and geometry constraints, because the fibre must route continuously through the section and around radii.
When continuous is the right call — honestly. If your part carries a high tensile or flexural load along one known direction, must replace a machined aluminium bracket like-for-like, and the budget supports it, continuous carbon fibre 3D printing is the better tool, and we'll tell you so when we see your model. We don't offer it — we'd rather lose the job than print the wrong technology for it.
For the great majority of stiffness-critical brackets, mounts, fixtures and airframe parts that cross our queue, chopped-fibre grades do the job at filament-printing prices. The grade table below is how we pick.
The fibre is the constant; the base polymer is the decision. All values are manufacturer TDS figures (ISO 527 / ISO 75, moulded specimens — printed parts are direction-dependent).
| Grade | Fibre loading | Tensile XY (dry) | Young's modulus XY (dry) | HDT @ 0.45 MPa | Pick it for |
|---|---|---|---|---|---|
| PLA-CF | 8% milled CF | 31.2 MPa | 3,281 MPa | 54°C | Matte-black jigs, camera fixtures, looks-first parts. Not a load grade — and we say so. |
| PETG-rCF08 | 8% recycled CF | 59.8 MPa | 3,710 MPa | 68.6°C | General workshop parts wanting a stiffness step over PETG, with recycled content. |
| PET-CF | 17% CF | 65.9 MPa* | 5,481 MPa* | 147.5°C | Dimensionally critical fixtures in humid environments — the driest CF we print. |
| PA12-CF | 10% CF | 77.4 MPa | 3,311 MPa | 131°C | The engineering default: moisture-immune, lowest anisotropy (1.48×), predictable everywhere. |
| PA612-CF | 15% CF | 91.9 MPa | 5,137 MPa | 175°C | Humid-service strength — keeps ~80% of its tensile wet. The balanced CF nylon. |
| PA6-CF | 20% CF | 115.3 MPa | 8,636 MPa | 215°C* | Peak stiffness, strength and heat for dry, climate-controlled service. |
| PPS-CF | 10% CF | 59.4 MPa* | 5,447 MPa* | 252.5°C | Chemical and heat extremes; UL 94 V-0 flame rating at 1.5 mm. |
*Post-anneal values — annealing is part of our process for these grades, not an optional extra. Source: Polymaker Fiberon / PolyLite TDS per grade (PA6-CF20 TDS V1.1, PLA-CF TDS V5.4, etc.) — full property tables, wet values and design rules on each grade page.
Three of these are carbon fibre nylons, and the nylon decision (PA6 vs PA612 vs PA12 — strength vs moisture) has its own page: see our nylon 3D printing hub. If your search started at "carbon-filled nylon", start there; the moisture column will decide your grade faster than the stiffness column will.
Two honest notes on the table. First, the biggest number is usually the wrong buy: PA6-CF's 8,636 MPa falls ~71% to 2,508 MPa when moisture-saturated, so for outdoor or humid service PA612-CF or PA12-CF beats it in the real world. Second, PLA-CF sits in the range because matte, zero-warp jigs are a legitimate job — not because it competes mechanically. Cheaper and better is still better.
The filament is only half the part. CF grades punish casual process control, which is most of what you're paying a bureau for.
This is also why two "carbon fibre" quotes can describe two different parts. If a price looks too good, ask what nozzle, what drying, what anneal and what orientation it includes.
Across all of it, the engineering review is the product: 9,500+ parts shipped this year, every quote checked by the team that prints it, rated 4.9★ from 34 Google reviews.
Carbon fibre is not the only reinforcement we print, and it's not always the right one. Glass fibre costs less and takes impact better; carbon is stiffer per gram. Unfilled polymers out-tough both.
| Chopped carbon fibre | Glass fibre | Unfilled base polymer | |
|---|---|---|---|
| Stiffness | Highest per loading — 3,281 to 8,636 MPa across our range | High — PA6-GF25 reaches 5,357 MPa, PET-GF15 4,144 MPa | Baseline — e.g. PETG 2,117 MPa |
| Impact toughness | The trade-off: fibres embrittle the matrix; notched impact drops | Better than CF at like-for-like loading — and PA6-GF's notched impact rises 10 → 28 kJ/m² wet | Best — unfilled grades flex instead of cracking |
| Cost band | Highest filament cost (CF nylons typically £60–130/kg) | Below the CF equivalent at similar performance | Lowest |
| Choose it when | Stiffness-to-weight or creep resistance is the requirement | Stiffness plus impact, on a budget — or any part that gets knocked, dropped or vibrated | Ductility, living hinges, snap fits, cosmetic parts |
Source: Polymaker Fiberon/PolyLite TDS values as published on our grade pages; ISO 527 / ISO 179, moulded specimens.
If your part needs stiffness and takes hits — gripper fingers, guards, brackets near moving stock — look at PA6-GF, PET-GF or PPS-GF before paying the carbon premium. We quote the cheaper reinforcement whenever it wins on the requirement, because engineers remember who talked them out of the expensive option.
Not sure which column you're in? That's the brief to send us. Browse the full range on the materials page, or skip ahead:
It's stiff more than it's strong. Chopped carbon fibre raises Young's modulus dramatically — our PA6-CF reaches 8,636 MPa, about 2.5× plain PLA — but tensile strength rises far less, and layer adhesion (Z-direction) is unchanged, so it remains the design limit. For stiffness-critical parts, CF is excellent. For impact or across-layer tension, it's the wrong buy, and we'll say so on your quote.
Chopped-fibre filaments (what we print) blend short carbon strands into the polymer: big stiffness gains at standard FDM pricing. Continuous-fibre systems embed an unbroken carbon strand along a programmed path: far higher tensile strength along that path, at substantially higher cost and with geometry constraints. We run chopped fibre only — if your load case genuinely needs continuous fibre, we'll tell you rather than sell you the wrong technology.
Start from the environment, not the headline number. Dry indoor service with peak stiffness and heat: PA6-CF. Humid or outdoor: PA612-CF (strength) or PA12-CF (dimensional stability — it's effectively moisture-immune). Precision fixtures near humidity: PET-CF. Chemical or heat extremes: PPS-CF. Light-duty jigs and looks: PLA-CF or PETG-rCF08. Or send the part and the service conditions, and our team picks for you.
Largely, yes. The fibres constrain the polymer as it cools, so CF grades shrink less and print noticeably flatter than their unfilled bases — one of the most practical reasons to specify them for large flat parts and fixtures. It reduces warp rather than abolishing it; geometry and process control still matter, which is why CF parts here run on dried filament with hardened nozzles and TDS-spec annealing.
No — we don't offer food-safe printing. That applies to every material we run, not just carbon fibre grades.
Carbon if the requirement is stiffness-to-weight or creep resistance. Glass if the part takes impact or the budget is tight: GF grades cost less and are tougher at similar loadings — PA6-GF's notched impact actually rises when the nylon absorbs moisture. Plenty of "carbon fibre" enquiries leave here as glass-fibre orders, with money saved and a tougher part shipped.
No — we're a 3D printing service, not a filament shop. We print customer parts in Polymaker Fiberon and PolyLite CF grades. If you're sourcing filament for your own printer, the manufacturer's TDS pages cover the spool data; if you'd rather skip the hardened-nozzle-and-drying learning curve, that's exactly the job we do.
Upload your model with peak load, service temperature and humidity exposure. Our team reviews every carbon fibre quote against the grade table above — and tells you if a cheaper material wins.
Printed in-house at our two UK workshops · 9,500+ parts shipped this year · 4.9★ from 34 Google reviews