This guide supports Extramet’s tungsten carbide machining services by answering the practical engineering and purchasing questions that usually come before an RFQ.
Quick Answer
- OD tolerance should be tied to function, not copied by habit.
- Tighter tolerances add setup, grinding, and inspection time.
- Roundness, straightness, and finish may matter as much as diameter.
| Requirement | Why it matters | Quote detail |
|---|---|---|
| Diameter tolerance | Controls fit and function | State finished OD |
| Roundness | Controls rotation and contact | Define measurement method |
| Straightness | Controls assembly and grinding behavior | Define allowable deviation |
| Finish | Controls friction and wear | Specify Ra or finish type |
Tolerance should match function
A carbide rod used as raw stock does not always need the same tolerance as a finished pin or gauge feature. Over-specifying tolerance can add cost without improving performance.
Diameter is not the only dimension
For precision carbide components, roundness, straightness, finish, end condition, and length can all affect assembly and function.
Inspection planning matters
If a customer needs a dimensional inspection report, the RFQ should define which dimensions are reported and how they are measured.
What to Include in an RFQ
- finished OD and tolerance
- roundness or straightness needs
- surface finish
- inspection report requirements
Related Extramet Resources
Reviewed for technical accuracy: This supporting article was prepared to align with Extramet’s tungsten carbide manufacturing, grinding, inspection, and quality capabilities in Latrobe, Pennsylvania.
Frequently Asked Questions
Can carbide be ground to very tight OD tolerances?
Yes, when geometry, grade, starting stock, and inspection requirements support the tolerance.
Does surface finish affect tolerance?
It can affect measurement and function, so finish should be specified separately.
Why include inspection method?
Different measurement methods can produce different practical interpretations of tight tolerances.