Prusa CORE One INDX Founders Get 'Hardened Steel' Nozzles That Aren't

Prusa Research has paused shipments of its CORE One+ INDX toolchanger conversion kits after Bondtech, the Swedish company that designed the system, admitted the nozzles included in Founders Edition boxes are not the hardened steel units originally promised.

The admission came to light after a Reddit user published a support email from Bondtech founder Martin Bondeus. In that email, Bondeus confirmed that manufacturing challenges prevented the company from machining the originally specified hardened steel nozzles reliably. The cutting tools could not withstand the process, so Bondtech substituted nitrocarburized steel nozzles without updating marketing materials.

What the Numbers Show

Bondtech batch-tested the shipped nozzles and reported hardness readings of 30 to 32 on the Rockwell C scale. True hardened steel nozzles typically land between 55 and 60 HRC. A standard brass nozzle, the baseline most users know, sits below 10 HRC. The nitrocarburized units sit in the middle: harder than brass, far softer than what buyers were led to expect.

Prusa engineers ran their own tests after the news broke. They found negligible wear after running five kilograms of carbon-fiber PETG through the nozzles. That changed quickly once they switched to Ultraglow, Prusa's super-abrasive glow-in-the-dark PETG. The protective coating failed after just 100 grams. Bondtech has acknowledged that abrasive filaments such as glass-fiber, carbon-fiber, metal-filled, and glow-in-the-dark materials will cause accelerated wear on the nitrocarburized nozzles.

No Quick Fix Available

Bondtech stated on its website that a concrete solution is not ready and that producing truly hardened INDX nozzles could take months. The INDX uses a bespoke induction-heated nozzle with no off-the-shelf replacement, which limits customer options. Bondtech is not offering compensation before it knows replacement costs and has asked customers to avoid returning the kits for now while they continue using non-abrasive materials.

Prusa responded by halting INDX kit shipments until mid-August and sent a statement to all customers with active INDX orders. The company said it preferred to wait for clearer information rather than ship kits while the nozzle question remained unresolved. Prusa also promised extra hardware at no charge to Founders Edition buyers who keep their orders, though it did not specify what that hardware would be.

Nozzlegate and Consumer Rights

A Founders Edition buyer who goes by Daddie0 built an entire website, Nozzlegate.com, to organize affected customers. He spent money on a consumer rights lawyer to make sure the guidance was accurate and consulted with ECC-Net, the European Consumer Centre network.

His argument centers on Swedish and EU consumer law rather than standard warranty policies. Under those rules, consumers who bought a product advertised with hardened steel nozzles have a right to a full or partial refund, and any return or exchange should happen at the seller's cost. The standard two-week return window most consumers know does not apply when the product description was materially incorrect. Daddie0 notes that consumers in all regions have a two-month window from the public announcement to claim a refund under Swedish law.

He also points out practical difficulties: customers who already installed the INDX before the news broke face a six-to-ten hour disassembly process to reverse the upgrade. Under EU consumer law, that burden falls on the seller when the product is found to be non-conforming.

What INDX Owners Should Do Now

If you own a Founders Edition INDX kit and have not yet installed it, hold off. Document your order and any communications from Bondtech or Prusa. If you have already installed the kit, avoid abrasive filaments until the companies clarify their replacement plan. Check the statute of limitations in your jurisdiction: EU and Swedish consumers have a two-month window from the public disclosure to act.

Prusa's CORE One+ INDX remains an interesting product in theory: eight toolheads swapping in seconds, built around a proven printer platform. The hardware works well for standard materials. The problem is that the product that shipped is not the product that was sold. Until Bondtech delivers a genuine hardened steel nozzle or a clear compensation path, anyone who paid for a Founders Edition kit should treat that purchase as unsettled.