Comparison
Capricorn XS Bowden PTFE Tubing vs Hardened Steel Nozzle Set (MK8): Which Is Better in 2026?
| At a glance | Capricorn XS Bowden PTFE Tubing | Hardened Steel Nozzle Set (MK8) |
|---|---|---|
| Rating | ★★★★⯨ 4.7/5 | ★★★★★ 4.4/5 |
| Price | $10-15 | $12-18 |
| Best for | Owners of Bowden-tube printers chasing cleaner prints. | Anyone printing CF, glow, or wood-fill filaments. |
| Guarantee | Amazon return policy applies | Amazon return policy applies |
| Check Today's Price → | Check Today's Price → |
Put these two side by side and you'll notice something the "vs" framing hides: they don't actually compete. Capricorn XS tubing fixes how filament gets *to* the hotend on a Bowden printer — less slop in the tube, crisper retraction, less stringing. A hardened steel MK8 nozzle set fixes what happens at the very tip, where abrasive filament grinds brass out of round. Different failure modes, different fixes, and at $10–18 apiece, this is closer to "which one first" than "which one instead."
So the honest version of the question is: what's actually going wrong with your prints?
The picks
Capricorn XS Bowden PTFE Tubing
A $12 upgrade that fixes inconsistent extrusion on Bowden printers.
$10-15 · Amazon return policy applies
The Capricorn XS runs $10–15 and holds a 4.7 rating for a reason. On a stock Ender-class Bowden machine, the factory tube has enough internal play that retraction gets vague, and that vagueness shows up as stringing, blobs, and walls that never look quite right no matter what you change in the slicer. The tighter bore of genuine Capricorn tubing takes that slack out, and it tolerates higher temperatures than cheap stock tube on top of it. Two warnings, both real: counterfeits are everywhere, so buy carefully, and if your printer is direct-drive, this upgrade does roughly nothing for you — the tube isn't doing the same job there.
Hardened Steel Nozzle Set (MK8)
Required if you print abrasive filaments — brass nozzles wear out fast.
$12-18 · Amazon return policy applies
The hardened steel set ($12–18, rated 4.4) is about wear, not print quality. Glow, wood-fill, carbon-fiber, and glitter filaments are loaded with particles that work like sandpaper on brass. A brass nozzle's bore opens up gradually, and quality drifts down so slowly that you'll blame your bed, your slicer, and your filament before you ever suspect the nozzle. Steel shrugs that abuse off. The multiple sizes are genuinely useful too — keep a 0.4mm in for general work and swap to a 0.6mm when you want faster draft parts. The trade-off is thermal: steel conducts heat worse than brass, so expect to run a touch hotter and accept slightly less efficient melting.
How to actually decide
Match the part to the symptom.
Stringing, oozing, or mushy retraction on a Bowden printer: tubing, no contest. It's the best value-per-dollar fix in this price class, and the improvement shows up on the next print.
Printing anything that sparkles or has fiber in it: nozzles, and not optionally. Running carbon-fiber filament through brass isn't an upgrade decision — it's a consumable cost you're forgetting to budget for.
Both symptoms: buy both. Together they cost less than most spools of the specialty filament that eats brass nozzles in the first place.
Who should skip each one
Skip the Capricorn if you run a direct-drive printer. That's not a knock on the product — it solves a Bowden-specific problem you simply don't have.
Skip the steel nozzles if you only ever print plain PLA. Brass is the better material for that job — better heat transfer, no downside — and a hardened nozzle is insurance against wear you'll never see. Buy the set the same day you buy your first abrasive spool, not before.
Bottom line
If I had to hand a Bowden-printer owner just one of these, it'd be the Capricorn — far more people have retraction problems than abrasive-filament ambitions, and its rating reflects that. But "better" is the wrong lens here. The tubing improves the prints you're already making; the nozzle set makes a whole category of filament survivable. Figure out which sentence describes you, and the choice makes itself.