FR4 FAQ: Common Questions Answered
This FAQ covers the most common questions engineers and buyers ask about FR4 (Glass-Epoxy Laminate (UL94 V-0)) when specifying machinable stock shapes. For full property data, see the FR4 material hub.
What is FR4?
FR4 (Glass-Epoxy Laminate (UL94 V-0)) is widely used in machined components and structural applications. It is supplied as extruded rod, sheet, plate, and tube. Read the FR4 material hub for the full chemistry and property profile.
What forms are available?
FR4 is stocked at FedMat in:
- Sheet/plate — see FR4 sheet sizes and tolerances
- Rod — see FR4 rod sizes and machining notes
- Tube — see FR4 tube sizes where applicable
For non-stock sizes, see Cut to Size and Get a Quote.
How does FR4 compare to similar materials?
The most common direct comparison is documented in the g10-vs-fr4 versus page, which covers property differences, application fit, and substitution criteria.
For a broader cross-material reference, browse the comparisons hub and the FR4 comparisons page.
What applications use FR4?
For typical applications and industry use cases, see FR4 applications and the Applications hub.
How is FR4 machined?
FR4 is machinable on standard CNC equipment. For tooling, feeds, and speeds guidance, see the machining guides cluster.
Where do I buy FR4?
FedMat stocks FR4 in standard sheet, rod, and tube formats with cut-to-size and machined-parts services. Request a quote with your dimensions, tolerance class, and quantity.
Request FR4 pricing and lead times
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