Application of the Month: World’s First Single-Piece 3D Printed Inconel Rocket Engine

We’ve seen plenty of 3D printed rocket engines in recent years. In 2025 alone, New Frontier Aerospace successfully tested one, while POLARIS Spaceplanes trialed a 3D printed aerospike engine. Other major players, from Relativity Space to Launcher and Orbex, are also betting on additive manufacturing to unlock designs that conventional methods can’t achieve. Against this backdrop, what makes this month’s Application of the Month stand out? Enter Chennai-based AgniKul Cosmos, which has unveiled what is claimed to be the world’s largest single-piece 3D printed Inconel rocket engine. About a meter long, the engine is printed as one fully integrated component, without welds, joints or fasteners, from fuel entry to plume exit.

So why does it matter that the engine was fabricated in a single piece? For one, it greatly reduces manufacturing complexity, cutting out the time-intensive steps of welding, joining or fastening multiple components. It also minimizes the risk of weak points or failure during operation. AgniKul reports that its integrated approach reduced production time by more than 60% while also lowering the engine’s weight, resulting in a more efficient design overall. Beyond speed and scalability, the single-piece structure improves durability and fluid flow, marking a significant leap over the company’s previous generations of engines.

The evolution of AgniKul Cosmos’ 3D printed engines, highlighting how large their latest one is by comparison

The choice of material is equally critical. The engine is made of Inconel, a nickel-chromium-based superalloy prized for its strength and ability to withstand extreme heat and pressure. These qualities make it particularly well-suited for rocket propulsion, where components must survive the intense conditions of launch and flight.