CNC Machining Requirements For Automotive Grille Molds

1) It is advised to minimize turning of parting surfaces and breakdown bosses as much as possible (take into account tool wear when choosing tools with longer livespan), when turning steep insertion surfaces that must be turned. For steep insertion surfaces that must be turned, first mill a section from their reference before turning in order to maintain alignment.

2) Spark pattern areas must not be processed with a light knife (pay special attention to controlling its path in small areas) and must allow a 0.2mm margin for processing. Furthermore, high voltage discharge processing should not take place directly.

3) Carefully consider whether the male and female mold reference edges coincide with the guide post hole positions before reestablishing them before proceeding to completion.

4) When finishing with a 3+2 machine tool, select tools and tool holders with as short a length as possible so as to limit error from rotating heads and limit how often parting surfaces rotate.

5) On the parting surface corresponding to an unbounded parting surface in female molds, leave an additional 0.03mm margin.



Grille-type mold cavities can be complex. To start off right, it is recommended that a 16r0.8 or 8R1 overall height of 0.15MM be used as the starting point!

Do not overlook the reference angle test!

D16R0.8 cutting parameters include speed 2000, feed 3000 and cutting depth of 0.3mm.

D8R1 Cutting Parameters include speed 4000 and feed 3000.

D4R0.5 tool with 0.15MM margin for corner cleaning

D4R0.5 cutting parameters: speed 6000, feed 2000 and cutting depth 0.12MM (maximum clamping 28MM and maximum effective 16MM).

D3R1.5 tool features a 0.15MM margin for corner processing.

D3R1.5 cutting parameters are as follows: speed 10000, feed 2000 and cutting depth 0.12MM (with maximum clamping diameter being 28MM and maximum effective size being 10MM).

8r4 offers a 0.08mm margin for 3D offset finishing! Molding is completely separate without an interface and the flow channel is sealed!

D8R4 cutting parameters: speed 9000, feed 3500 and depth of cut of 0.5MM.

A 0.08mm margin is left on the D4R2 tool to allow for finishing with a corner-cleaning tool path and high-definition corners such as partial V-angles to be processed successfully.

D4R2 cutting parameters: speed 9000, feed 2200 and cutting depth 0.15MM (maximum clamping 28MM and effective 12MM).

Allow a margin of 0.08mm for the D2R1 tool and employ a fine finishing tool path to process corners with high definition corners such as V-shaped ones.

D2R1 Cutting Parameters: Speed 12000, Feed 1700 and Cutting Depth 0.08MM (maximum clamping 28MM and maximum effective 8MM).


Break through all the processing in the mouth and exposed areas of the parting surface!

Tests must be run to ensure accurate dimensions!

The R2 tool was used to mill out the middle large breakdown, while areas not milled are connected using angles.

If time is of the essence and knife paths are scattered, select the molding point to help.

Precision parting surface and peripheral parting surface!

Choose D8R4 or D4R2 tool for finishing.


Corner cleaning should include milling all sharp corners on the parting surface to a minimum depth of r0.5, and, ideally, to as little as r0.25!

Finally, don’t overlook the shape, such as a height plate, pin hole platform and cutting. If there’s a wear-resistant plate for precise positioning purposes – be sure to pull it!

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