In Episode 10 of The PM Blend, the Atlas team takes a closer look at machinability – what it is, why it matters in powder metallurgy, and how machining supports the final performance and precision of PM parts. While PM is known for near-net-shape capabilities, machining still plays a key role in finishing certain features and meeting tighter requirements.
Below is an article version of the conversation, closely following the insights shared by Mark Powell, Joe Pfingstler, Dom Bevak, Tom Pfingstler, and Rob Powell.
Machinability refers to how easily a material can be machined. As Dom explains, several factors influence machinability in PM:
All of these determine how a tool engages with the material and which cutting conditions are needed.
Even though PM aims to create parts that are as close to the final shape as possible, some features simply can’t be molded in.
Machining becomes necessary when parts require design features and enhancements like:
Some features also cannot be formed because the part cannot be ejected cleanly from the mold, or because thin tooling sections would be too weak.
Machining fills these gaps and ensures that PM parts meet the exact requirements needed for the application.
As the team outlines, machining may be used for:
The type of machining performed depends on the feature, the tolerance, and how the part was molded.
Tom and Rob note that material behavior plays an important role in machinability. Factors include:
Resin impregnation may also be used in certain cases to support machining needs, depending on how the part has been processed.
Some raw materials also include machining additives that improve machinability, which the materials team evaluates based on the part and performance requirements.
Dom explains that tool selection is primarily driven by the material being machined.
Atlas commonly uses:
Both the tool geometry and the feature being produced play significant roles in determining the setup.
During the episode, the team highlights two components used in heavy-duty truck applications.
To create the parts, Atlas first created PM blanks that allowed the team to handle the remaining details through machining:
In one component, the teeth had to be molded to full height. Machining then reduced a thin top section to its final dimension since forming the teeth only partway up the wall would have made the tooling too thin.
This combination of molding and machining allowed Atlas to deliver the required strength, consistency, and cost savings.
As Dom shares, tooling vendors continue advancing their solutions with:
Atlas works closely with vendors to match tool selection to each part’s material and machining requirements.
Fixturing is another essential part of machining PM components. Dom and the tooling department design most fixtures in-house, with around 80% produced internally. Fixture design depends on the geometry, the machine, and what features need to be accessed.
The team highlighted several ways they continue improving machining outcomes:
As Joe notes, Atlas aims to help customers make their components more effective and competitive, not simply reject complex parts.
Machinability is an essential part of powder metallurgy. While PM brings the advantage of forming complex shapes efficiently, machining ensures that final parts meet the exact tolerances, fit, and function required.
When machining and PM work together, manufacturers benefit from consistent performance, reliable assembly, and substantial cost savings, especially for parts that were previously machined or cast.