# What is Surface Finish Ra?

Roughness average in micrometers. Tells inspectors how smooth a machined surface must be.

## In real work

Print calls Ra 1.6 on the bore. Hit it or the NDT hold stays open.

## Related terms

- [NIMS Credential](https://prompthausapp.com/learn/nims-credential.md)
- [G-code](https://prompthausapp.com/learn/g-code.md)
- [CNC Setup](https://prompthausapp.com/learn/cnc-setup.md)
- [Credentialing Achievement Record](https://prompthausapp.com/learn/credentialing-achievement-record.md)
- [Submarine Industrial Base](https://prompthausapp.com/learn/submarine-industrial-base.md)

## How is this different from Googling it?

Google gives a definition. Prompthaus pairs each term with how it shows up in standups, PRs, prompts, and design reviews—then quizzes you until the word sticks. One term a day on iPhone.

- Category: Manufacturing
- HTML: https://prompthausapp.com/learn/surface-finish-ra
- App Store: https://apps.apple.com/us/app/prompthaus-ai-vocabulary/id6776314407