In chapter 5 lesson 9, Jake introduces countersinking, a key secondary operation used to give your parts a clean, flush appearance while improving function and fit. You’ll learn what a countersink is, how it works, and how to design holes that properly accommodate flat-head screws without protruding above the surface.

Jake explains the difference between 82° (imperial) and 90° (metric) countersinks, the roles of major and minor diameters, and how SendCutSend automatically applies these standards during checkout. He also covers material and size limitations, including minimum part thickness and maximum part dimensions for countersinking, and which materials are compatible with the process.

Finally, you’ll see how to model a countersink in CAD, understand how hole resizing works within SendCutSend’s workflow, and what to expect from your finished parts, such as minor marks or residue from secondary machining.

What You’ll Learn:

• What countersinking is and when to use it
• The difference between 82° and 90° countersinks
• How to design and size holes for flat-head hardware
• Material, size, and thickness limits for countersinking
• How SendCutSend automatically adjusts holes during checkout
• How to model and verify a countersink in your CAD design

Additional resources:
Countersinking Design Guidelines
The Benefits of Countersinking
Designing for Countersinking