CNC Processes

CNC Milling

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Milling with Fictiv (1:23)

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CNC Milling Materials

A2 Tool Steel






Cast Iron



Garolite G-10








Stainless Steel





A2 Tool Steel

A2 Tool Steel has excellent wear resistance and toughness, commonly used to make fixtures, tools, tool holders, gauges, and punches.
Mill Lead Time:
As fast as 7 days
Finishing Options:
Media Blasting, Vibratory Tumbling, Black Oxide, Powdercoating

Finishing Options for CNC Milling

Name Applicable Materials Colors Can be applied with
Alodine Aluminum Clear, gold Media Blasting, Tumbling, Type II Anodizing* Type III Anodizing*, Type III Anodizing with PTFE*
Anodizing Aluminum Clear, black, grey, red, blue, gold Media Blasting, Tumbling, Alodine*
Black Oxide Steel, Stainless Steel Black Media Blasting, Tumbling, Passivation
Electroless Nickel Plating Aluminum, Steel, Stainless Steel Media Blasting, Tumbling
Electropolishing Steel, Stainless Steel
Hand Polishing Acrylic Enhanced cosmetic appearance
Media Blasting Aluminum, Steel, Stainless Steel, Brass, Bronze, Copper All post processes except Electropolish and Powdercoat
Nickel Plating Aluminum, Steel, Stainless Steel Media Blasting, Tumbling
Passivation Steel, Stainless Steel Black Oxide, Electroless Nickel Plating, Zinc Plating, Tumbling, Media Blasting
Powder Coating Aluminum, Steel, Stainless Steel Black (20% or 90% gloss), white (20% or 90% gloss)
Tumbling Aluminum, Steel, Stainless Steel, Brass, Bronze, Copper All post processes except Electropolish and Powdercoat
Vapor Polishing CNC Polycarbonate (Clear, Black) Enhanced cosmetic appearance, near optically clear applications
Zinc Plating Steel, Stainless Steel Clear: light blue coating, black: glossy black coating Media Blasting, Tumbling, Passivation

* = requires masking

Precision Machining Tolerance

Metals, PEEK, And
ULTEM With Drawing
Other Plastics
With Drawing
No Drawing
Linear Dimension +/- 0.01 mm
+/-0.0003 inch
+/- 0.05 mm
+/- 0.002 inch
ISO 2768 Medium
Hole Diameters
(Not Reamed)
+/- 0.008 mm
+/- 0.0003 inch
+/- 0.05 mm
+/- 0.002 inch
ISO 2768 Medium
Shaft Diameters +/- 0.004 mm
+/-0.00016 inch
+/- 0.05 mm
+/- 0.002 inch
ISO 2768 Medium

Depending on the machining process, Fictiv accepts parts up to 48" in length. If you have larger parts, please chat with our team. Also note that the tolerances listed here are minimums for an ideal case and looser tolerances may be required depending on the process, material choice, or part geometry.

Download Tolerance Chart

Milled Plate for HEBI Robotics

Production Location

AS-9100 Certified Overseas Manufacturing Partner

Secondary Processes

Heat Treating, Anodizing Type II, Media Blasting

Quantity of Parts Made


“Working with Fictiv, we can get instant communication. It really helps us quickly iterate, talk through things on our parts that may need to change, and even get updates on parts and shipments.”
Andrew Willing, Mechanical Engineer at Hebi Robotics

Accelerate Development with Fictiv CNC Manufacturing

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  • Tight tolerances
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  • DFM feedback to optimize your designs
  • On-demand production updates
  • Wide range of materials and finishing options
  • Material certifications & certificates of conformity
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  • Free dimensional inspection reports
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About the CNC Milling Process

With milling, the stock that the part will be cut from is usually a six-sided bar or sheet of material (though it can be also a cylindrical rodi). This stock is fixtured to the bed of the machine and the features of the part are cut using a rotating tool such as a drill or endmill.

Key Aspects of 3-Axis Machining

  • The rotating tool can translate relative to the part on X, Y, and Z axes
  • The tool is fixed in a vertical or horizontal (depending on the machine) position
  • With modern CNC mills, the tool can move in any combination of the 3 axes simultaneously

Key Aspects of 5-Axis Machining

  • Capable of the same movements as 3-axes, but with added rotation on X and Y axes
  • Typically it is the bed that rotates rather than the toolhead
  • The added rotation allows for much more freedon when machining each setup

CNC Milling FAQs

Technical FAQs

Does Fictiv vapor polish ABS or other plastics?

At this time, we do not vapor polish ABS, we only vapor polish Polycarbonate and manual polish Acrylic

What minimum thickness can I incorporate into my design to prevent warpage?

Typically, we recommend a minimum wall thickness of 0.5mm for metals and 1mm for plastics. However, these values largely depend on the size of the part; therefore the larger the part size, the higher the recommended minimum wall thickness should be. Please keep in mind that this does not imply that wall thicknesses with lesser values are unachievable. These recommendations are simply thresholds to limit the risk of warpage.

What size of fillets are added when no specific fillet is specified by the 3D model or drawing?

If a specific fillet radius is required, please specify. If not, the fillet radii that allow for easy machining will be added based on the machinist’s discretion. For a general idea, internal vertical edge radii could be >1/3*Depth and internal horizontal edges may be left sharp or have a 0.5mm to 1mm radius.

General FAQs

What is tool offset in CNC milling?

CNC machines must be programmed to allow offsets for the diameter and length of the tool to cut the part. By knowing the exact tool offsets a machinist can find the precise machining starting point.

What is the difference between CNC turning and CNC milling?

The CNC milling process involves a rotating tool that carves away excess material from a stationary workpiece.

CNC turning uses a rotating workpiece, typically used to make cylindrical parts.

What is 5-axis CNC machining?

A 5-axis CNC milling machine can move a cutting tool in 5 axes, which allows the operator to simultaneously hit five different sides (or more) of a part depending on the design complexities. Resultantly, the tool is highly capable of creating highly complex products and parts.

With a 5-axis machine, the X, Y, and Z-axes are similar to a 3-axis machine layout. The table then rotates along the A-axis, as it does with the 4-axis. However, the 5-axis machine involves the pivoting action at the joint of the table, followed by rotation along the C-axis, which defines the fifth movement.

What is the difference between a CNC router and a CNC mill?

A CNC router moves the spindle around a stationary table and is primarily designed to operate at high speeds.

A CNC mill typically moves the workpiece along a linear axis, making cuts through the driving force of rotational speed.

What types of materials do CNC mills use?

The most commonly used materials in CNC milling are metals, such as aluminum, brass or steel and plastics such as ABS, acrylic, polycarbonate, and polypropylene.

Top Resources for CNC Milling


CNC Machining Design Guide


DFM for CNC Machining


Getting Started with CNC Milling

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