How Material Choice Affects Machining Time and Part Cost
At Focused on Machining, we work with a wide range of materials, from aluminum to Inconel to A286. But one thing we always make clear to customers is that these materials differ not only in their performance, but also in their machinability. Material choice can directly impact factors like cycle time and tooling, ultimately driving part cost.
Learn how the machining process changes, and why that leads to higher prices.
Why Material Choice Affects Machining Time
On the machinability spectrum, aluminum is relatively easy to cut, while Inconel machining is much more demanding. Aluminum allows for aggressive machining, but Inconel does not.
This is reflected in quotes, as machine shop pricing is closely tied to time. Longer machining time means higher cost. At Focused on Machining, price is heavily tied to production hours and shop rate. But other material factors do add to price, as well; for instance, materials like Inconel are significantly more expensive, while specialized tools may be needed because tool wear can be more severe.
Comparing Aluminum and Inconel on the Same Part
We have never machined the exact same part in both aluminum and Inconel, so a perfect one-to-one comparison is difficult. But a hypothetical example still helps illustrate the difference.
For this hypothetical, we considered machining a part that is 4” x 4” x 1” with a 0.5” end mill to rough it.
With aluminum, especially 6000 series aluminum, we can typically use tooling designed for high material removal rates. For a hypothetical part, that might mean a half-inch three-flute tool taking deep cuts at high RPMs and aggressive stepovers. Because aluminum is comparatively soft and easy to machine, we can remove material quickly and efficiently.
Inconel requires a much different approach. For the same part made of Inconel, we would likely use a five-flute or seven-flute tool with much more conservative cutting parameters. The depth of cut would be shallower and RPMs would be reduced. Additionally, heat control becomes critical with Inconel because of the potential for work hardening.
Quantifying the Difference: A 17x Change
In qualitative terms, aluminum lets you cut fast, while Inconel forces you to slow down. But quantitatively, a simple back-of-the-envelope calculation suggests that machining the part from Inconel 718 would take roughly 17 times longer than machining the same part in 6061 aluminum.
That’s just an estimate, but it certainly aligns with our general experience. A very simple part like this that might take minutes in aluminum could take close to an hour in Inconel. And that difference becomes especially important in our production machining services, when the gap multiplies significantly across hundreds or thousands of pieces.
Experience Is Critical With Difficult Materials
When a project involves Inconel, A286, or other difficult materials, experience matters. An expert shop understands how to move as fast as possible without risking scrap and rework.
At our precision machine shop, we have years of experience machining challenging materials. We understand the risks, and we know the best techniques to be as efficient as possible for our customers.
If you’re looking for Inconel, A286, or titanium machining, let’s discuss the best approach for your project. Contact us today!