Picture a titanium bracket sitting finished on a bench. Next to it, in the bin, is a heap of shiny chips that used to be the rest of the block. Most of what the shop bought is in that bin. In aerospace, where the metal is expensive and weight is everything, that’s a hard number to ignore. It’s a big reason teams are looking at metal additive manufacturing for parts they’ve always machined. Nobody’s closing the machine shop. They’re just sorting out which parts belong where.
What Pushes Aerospace Teams to Look Beyond Traditional Machining
Machining starts big and cuts down. For some flight parts, most of the metal bought ends up as scrap. There’s even a term for it, the buy-to-fly ratio, which compares the weight of raw stock to the weight of the finished part. Titanium and nickel alloys cost a lot, so a high ratio really stings.
Time is the other pain. Casting and forging need tooling, and tooling takes months and real money, even for a handful of parts. Complicated shapes add more setups, each one eating hours. For small runs, test hardware and spares, the old routes feel slow.
Benefits That Metal Additive Manufacturing Brings to Flight Hardware
AME’s Services page names four benefits of printing: decreased cost, integrated parts, decreased weight and reduced materials. Here’s roughly what each one means on a real part:
- Cost: No tooling and less wasted metal can help on complex parts made in small numbers.
- Integrated parts: Several pieces can sometimes become one, which means fewer fasteners, fewer joints and less assembly.
- Weight: Metal goes only where the loads need it, in shapes a cutter can’t reach.
- Materials: Printing builds a part up. Machining carves it down.
- Prototypes: Change the file, print again. No new tooling.
Where Machining Still Holds the Advantage
Printing isn’t always the smarter pick. Machined surfaces come out smoother and hold tighter tolerances right off the machine. Simple parts made by the thousand are usually cheaper to cut. Some parts are just too big for a printer’s build volume. And machining has decades of data behind it, which makes sign-off easier. A printed part has to earn that trust with testing and inspection.
Why Many Teams Combine Printing and Machining in One Workflow
A lot of teams quit framing it as printing versus machining. They print a near-net shape, a rough part close to final size, and then machine the surfaces that need to be exact, like bores, sealing faces and mounting holes.
Designers leave a little extra metal on those spots so the machinist has something to cut. Heat treatment or hot isostatic pressing usually comes before the final machining so that the part is stable and dense by the time the precise work starts. Each process gets the job it’s best at.
How Additive Manufacturing & Engineering Supports Aerospace Customers
Additive Manufacturing & Engineering, or AME, is a metal printing shop in Huntsville, Alabama, working for aerospace, defense, energy and manufacturing customers. Its Services page shows NASA, Blue Origin, the Department of Defense and Mountain Aerospace Research Solutions among select clients, and says it helps inventors, makers and start-ups too.
The shop prints on an EOS M400 using laser powder bed fusion, with a build volume up to 400 mm per side, in Inconel 718 and GRCop-42. Other metals are available on request when volume requirements are met. AME is AS9100D and ISO 9001 certified and ITAR registered, and its homepage lists design optimization, metallurgy analysis and structural CAD. Customers bring CAD files, and the shop takes it from there.
FAQs
Why are aerospace companies switching from machined parts to 3D printed metal parts?
Mostly for weight, waste and speed on small runs. Printing can merge pieces and reach shapes a cutter can’t, with no tooling. It’s no full replacement, though. Teams usually print complex parts and keep machining anything simple or tight on tolerances, where cutting is still cheaper. Case by case.
Are 3D printed metal parts as strong as machined parts?
Yes, they can be under the right conditions. However, the final quality depends heavily on how the metal is built and finished, even if the material is quite dense and is further densified with processes like hot isostatic pressing (HIP). As a result, critical metal printed parts are subjected to a lot of testing before they are ever used.
What does buy-to-fly ratio mean in aerospace manufacturing?
It’s the weight of the raw metal bought divided by the weight of the part that actually flies. A high number means most of the metal got cut off as scrap. Printing adds metal only where it’s needed, so it can bring that number down, especially with costly alloys like titanium.
Does a printed aerospace part still need machining?
Printed parts tend to have rougher surfaces compared to parts made using machined processes. As a result, operations such as threading, sealing, and mounting are typically done using machining processes. This is because these parts require high levels of surface smoothness. In such cases, the designers add extra material in those sections. While the printing process takes care of complex designs, machining processes handle precision work. Early consultation with your service provider is always recommended.
What certifications should an aerospace team look for in a metal 3D printing provider?
AS9100D, the aerospace quality standard, is a common ask, often with ISO 9001. Defense work can also need ITAR registration. AME lists all three. Teams should ask about material certificates, inspection methods and record-keeping too, since flight hardware usually needs full traceability. That paper trail matters.