Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3)

nikolaj_t — Sat, 11 Apr 2026 21:00:41 GMT

Hi everyone,

I'm unable to add a Trapezoidal Thread Mill to my library due to a geometric validation error.

Tool Specs:

Type: Thread Mill
Diameter: 7.4 mm
Thread Pitch: 3.0 mm
Included Angle: 30 deg
Tip Width: 1.02 mm

The Issue: Fusion 360 throws the warning: "Thread pitch is more than the tool's maximum thread pitch".

The software forces me to increase the tool diameter to 11.2 mm before it will accept the 3.0 mm pitch. However, my physical tool is exactly 7.4 mm. I cannot "lie" about the diameter in the library, as I need the G-code to reflect the actual tool size for accurate toolpaths.

I have tried the workarounds in this article, such as reducing the shaft diameter, but the error persists. It seems the validator prevents small-diameter tools from having a high pitch, even if they exist physically.

Is there a way to bypass this validation or a known workaround that keeps the correct 7.4 mm diameter and 30 degrees?

Re: Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3)

programming2C78B — Mon, 13 Apr 2026 11:19:31 GMT

Are you against the idea of just making it a Form Tool?

Re: Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3)

seth.madore — Mon, 20 Apr 2026 14:25:42 GMT

Yep, this appears to be a mathematical error, I've logged CAM-72027 to investigate this.

As @programming2C78B suggests, a Form Mill will give you exactly what you need (as a workaround)

topic Re: Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3) in Fusion Manufacture Forum

Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3)

Re: Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3)

Re: Geometric validation error: Thread Pitch vs. Tool Diameter (TR14x3)