06/23/2026
Surface finish is one of those details that’s easy to overlook—until it affects performance, cost, or lead time.
A smoother finish isn’t always better.
In fact, specifying a finer surface finish than your application actually requires can add unnecessary machining time, secondary operations, and cost.
That’s why understanding surface finish matters:
🔹 Lower Ra values produce smoother surfaces
🔹 Different manufacturing processes achieve different finish ranges
🔹 Surface finish can impact sealing, friction, wear resistance, and appearance
🔹 The right finish balances performance, manufacturability, and cost
For example, a component that functions perfectly at Ra 3.2 μm may not benefit from being polished to Ra 0.2 μm—but it will likely cost more to produce.
The goal isn’t to achieve the smoothest possible finish.
The goal is to achieve the right finish for the application.
We’ve put together this visual guide to help simplify surface finish specifications and show how different manufacturing processes influence the final result.
Have you ever seen a part become more expensive because it was over-specified?