---
title: "G10 & FR4 Machining | Glass-Epoxy Laminate Parts | OpenSpindle"
description: "Get quotes for custom G10 and FR4 parts from independent machine shops. Glass-epoxy laminate that is strong, dimensionally stable, and an excellent electrical insulator. Upload a drawing."
canonical: https://openspindle.com/materials/g10-fr4
---

# Custom G10 and FR4 parts from independent machine shops

G10 and FR4 are glass-epoxy laminates: strong for their weight, dimensionally stable, and among the best machinable electrical insulators. Upload a drawing and hear back from shops that cut and machine glass-epoxy sheet every day.

## G10 / FR4 shops on OpenSpindle

Real shops that machine and cut glass-epoxy laminate. See their equipment and talk to the person making your part.

[Browse all G10 / FR4 shops](https://openspindle.com/manufacturers?material=G10%20%2F%20FR4)

## G10 and FR4 grades shops run most

The grade sets flammability rating, temperature limit, and cost. These are the ones you will see quoted; if yours is not here, ask when you request a quote.

### G10

The general-purpose high-strength grade. Glass-fabric-reinforced epoxy with excellent mechanical strength, dimensional stability, and electrical insulation. Machines cleanly and is stocked widely in sheet.

**Best for:** Structural insulators, spacers, fixtures, general parts

### FR4

The flame-retardant version of G10, rated UL94 V-0 (self-extinguishing). Mechanically and electrically very similar to G10 and is the standard PCB substrate. The default choice where flammability matters.

**Best for:** PCB substrates, electrical panels, parts needing a flame rating

### G11

A higher-temperature epoxy laminate that holds more of its strength at elevated temperature than G10. Costs more and is less commonly stocked, specified when service temperature runs high.

**Best for:** Elevated-temperature insulators and structural parts

### Garolite

A common trade name used interchangeably for G10 and FR4 glass-epoxy laminate. Not a separate material; the underlying grade is still G10 or FR4, so confirm which one your spec needs.

**Best for:** Any G10 / FR4 application, under a different name

## Material Properties

Representative values for FR4 / G10 glass-epoxy laminate. Exact numbers vary by grade, resin, and glass content.

| Property | Value |
| --- | --- |
| Density | ~1.80 g/cm³ (0.065 lb/in³) |
| Tensile strength | ~35-45 ksi (240-310 MPa) |
| Flexural strength | ~50-70 ksi (345-480 MPa) |
| Max continuous service temp | ~130-140 °C (265-285 °F) for FR4 |
| Dielectric strength | Very high; excellent electrical insulator |
| Water absorption | Very low, ~0.1% |
| Machinability | Machines cleanly but highly abrasive; dulls tooling fast |

The glass fibers that make G10 and FR4 strong also make them abrasive, so shops run carbide or diamond tooling. The epoxy-glass dust is a respiratory and skin irritant, so parts are cut wet or with dust extraction.

## Processes That Run This Material

- [CNC Machining](https://openspindle.com/capabilities/cnc-machining.md) -- Milled insulators, standoffs, and prismatic parts from sheet.
- [CNC Routing](https://openspindle.com/capabilities/cnc-routing.md) -- Flat profiling and pockets in glass-epoxy sheet with dust extraction.
- [Waterjet Cutting](https://openspindle.com/capabilities/waterjet-cutting.md) -- Ideal for G10 / FR4: no heat, no dust, and clean edges through thick laminate.

## Finishes

G10 and FR4 normally ship as-machined. There is no plating or anodize; finishing is about edge quality and handling.

- **As-machined** -- The standard state. The laminate is dense and stable straight off the machine, and is fine for insulators, spacers, and structural parts.
- **Sealed edges** -- Machined edges expose glass fibers and can wick moisture. Sealing the edges is used where the part sees humidity or fluids.
- **Color** -- G10 and FR4 come in natural (green, tan, or off-white). Color is inherent to the sheet, not applied, so specify the stock color if it matters.

G10 and FR4 should not be laser cut: the epoxy releases toxic fumes and chars the edge. Waterjet, machining, or routing are the preferred processes.

## Applications

- PCBs & electrical insulators
- Standoffs & washers
- Battery & EV insulation
- Knife handle scales
- Drone & RC frames
- Tooling & fixtures
- Structural spacers

G10 and FR4 show up wherever a part must be strong, stable, and electrically insulating at the same time.

## How It Compares

How G10 / FR4 stacks up against the other composites and plastics shops quote most.

### [Carbon fiber](https://openspindle.com/carbon-fiber-cutting.md)

- Carbon fiber is stiffer and lighter for the same part
- G10 / FR4 is an electrical insulator, while carbon fiber is conductive
- G10 / FR4 costs much less and is easier to source in plain sheet

**Verdict:** Choose G10 / FR4 for insulating, cost-sensitive parts. Choose carbon fiber when maximum stiffness-to-weight justifies the price and conductivity is acceptable.

### [Phenolic](https://openspindle.com/materials/phenolic.md)

- G10 / FR4 is stronger and holds up to higher temperature
- Phenolic machines more easily and has better wear and bearing performance
- Both are good electrical insulators; the glass-epoxy resists moisture better

**Verdict:** Choose G10 / FR4 for strength and temperature. Choose phenolic for easier machining and wear surfaces such as bushings and gears.

## Frequently Asked Questions

### What is the difference between G10 and FR4?

They are the same base material, a glass-fabric-reinforced epoxy laminate, with one difference: FR4 is flame-retardant and rated UL94 V-0 (self-extinguishing), while standard G10 is not. Their mechanical and electrical properties are nearly identical. Use FR4 when a flammability rating is required, such as in electronics, and G10 when it is not.

### Is G10 / FR4 a good electrical insulator?

Yes. Glass-epoxy laminate has very high dielectric strength and low moisture absorption, which is why FR4 is the standard printed-circuit-board substrate. It insulates well across a wide temperature range and stays dimensionally stable. It is a common choice for standoffs, panels, and battery insulation.

### Why does G10 / FR4 wear out cutting tools so fast?

The glass fibers that reinforce the epoxy are abrasive and dull steel tooling quickly. Shops run carbide or diamond-coated tooling and adjust feeds and speeds to get clean edges and reasonable tool life. Expect glass-epoxy machining to cost more per part than a soft plastic for this reason.

### Can G10 / FR4 be laser cut?

It should not be. The epoxy resin releases toxic fumes when burned and the laser chars and delaminates the edge. Waterjet cutting is ideal because it uses no heat and generates no dust, and CNC machining or routing with extraction also works well. Ask your shop which process fits your part.

### Is machining G10 / FR4 dust hazardous?

The dust is a respiratory and skin irritant, so shops cut the material wet or use dust extraction and protective equipment. This is a normal, well-understood part of machining glass-epoxy and does not affect the finished part. No special handling is needed once the part is cut and cleaned.

### How does G10 / FR4 compare to carbon fiber?

Carbon fiber is stiffer and lighter, but it is electrically conductive and much more expensive. G10 / FR4 is an electrical insulator, costs far less, and is easy to buy in plain sheet. Choose carbon fiber for maximum stiffness-to-weight and G10 / FR4 when you need insulation, dimensional stability, and lower cost.

### What file formats should I send for a G10 / FR4 part?

STEP, IGES, X_T, DWG, DXF, or a dimensioned PDF. Note the grade (G10 or FR4), sheet thickness, critical dimensions and their tolerances, quantity, and whether the part needs a flame rating. Flag any edges that must be sealed for moisture exposure.

## Related Materials

- [Carbon Fiber](https://openspindle.com/carbon-fiber-cutting.md)
- [Phenolic](https://openspindle.com/materials/phenolic.md)
- [PEEK](https://openspindle.com/materials/peek.md)
- [Delrin](https://openspindle.com/materials/delrin.md)
- [Nylon](https://openspindle.com/materials/nylon.md)
- [Aluminum](https://openspindle.com/materials/aluminum.md)

## Get G10 / FR4 part quotes

Upload a drawing once and compare quotes from independent shops that machine and cut glass-epoxy laminate.