Extrusion

Extrusion is a manufacturing process that forces material through a die to produce a long part with a constant cross-sectional profile. In CNC and millwork contexts, extrusion creates near-net-shape blanks that are later cut, drilled, milled, tapped, or sawn to final features and tolerances. It is used for aluminum profiles, channels, tubes, and architectural components.

On the shop floor, extrusion feeds the CNC cell as stock that already has its long, uniform cross-section. The operator cuts the profile to manageable lengths, then fixtures it while respecting cosmetic surfaces and the dimensional limits of the as-extruded part. Machining adds what the die cannot: precision holes, slots, pockets, tapped bosses, end trims, and datum faces. Because extrusion tolerances are broader than machined tolerances, the setup references a reliable as-extruded datum, but final critical datums are established by CNC operations. Typical workflow is extrude, quench, cut to length, fixture, CNC machine, deburr, inspect, and finish with anodizing or coating. This makes economic sense when the part has a long uniform section and only a few regions need tight positional accuracy or complex secondary features. Understanding material condition from forming and cooling matters, because residual stress affects how the profile behaves under clamping and cutting.

• ⚠️Twisted or bowed profile after machining: Uneven cooling during extrusion or excessive clamp pressure in the CNC leaves the part distorted, causing hole misalignment and poor assembly fit.
• ⚠️Inaccurate hole patterns and pocket locations: Choosing an unreliable as-extruded face as the setup datum shifts all machined features relative to the mating assembly, because extrusion tolerance is not final machined tolerance.
• ⚠️Marred surfaces and sharp edges: Soft aluminum extrusions scratch easily during handling, sawing, or clamping, while poor deburring leaves edges that interfere with anodizing and cause assembly defects.