Are Our Heat-Set Insert Datasheets Wrong? CNC Kitchen Puts Them to the Test

The Problem With Heat-Set Insert Datasheets

Heat-set inserts are a staple in functional 3D printing, enabling strong metal threading in plastic parts. But what if the recommended hole sizes are wrong?

CNC Kitchen recently put popular heat-set insert datasheets to the test, measuring actual pull-out strength across different hole diameters.

What the Testing Revealed

The video tests multiple hole sizes against manufacturer recommendations, measuring both installation ease and pull-out force. The results challenge conventional wisdom about optimal sizing.

Key Findings

• Manufacturer recommended holes may be too large, reducing pull-out strength
• Smaller holes than recommended can actually perform better in some cases
• Material brand matters — different manufacturers have different optimal ranges

What This Means for Makers

If you are designing parts with heat-set inserts, do not blindly follow datasheets. Consider testing your specific hole size with your specific inserts and filament. The video provides a methodology for accurate testing.

For functional prints where strength matters, a little experimentation can significantly improve results.