CNC Machining in Garolite G-10
Garolite G-10 is a glass-reinforced epoxy composite with a high strength-to-weight ratio, and excellent corrosion and moisture resistance, making it ideal for marine applications. It is also fire-resistant and a great electrical insulator, making it a material of choice for electronic circuit board substrates.

About Garolite G-10 for CNC Machining
Garolite G-10 is a thermoset composite made from fiberglass and phenolic epoxy resin. As a thermoset, G-10 cannot be melted and reformed. If it is heated above its peak operating temperature it breaks down chemically and will not retain its properties once cooled. This makes injection molding in garolite impossible. CNC machining in Garolite G-10 is the only method of manufacturing complex parts with this material.
Application | Terminal boards, knife handles, jigs and fixtures, engine mountings |
Advantages | Insulating, fire resistant, low maintenance, high strength-to-weight ratio, moisture resistant, dimensionally stable |
Disadvantages | Properties break down under prolonged exposure to UV light |
Lead Time | Lead time is generally a minimum of 3 days. However, this can increase depending on complexity and manufacturing origin. |
Price | $$$ |
Tolerances | Machining tolerances of 0.005” (0.13mm) are achievable. |
Wall Thickness | A minimum wall thickness of 0.03” (0.8mm) is achievable. This can vary depending on the ratio of wall thickness to planar dimension. |
Max Part Size | The maximum size of the part is determined by the machines available and the complexity of the part. |
Garolite G-10
CNC machining in Garolite G-10 produces parts that are ideal for corrosive or high-moisture applications. Typically, these combinations of environmental conditions are found in the marine industry where G-10 is used for engine components such as mounting brackets as well as for applications that require electrical insulation and mechanical strength.
Tensile Strength, Yield (MPa) | Compressive Strength (MPa) | Hardness (Rockwell M) | Flammability Rating | Glass Transition Temperature (°C) |
---|---|---|---|---|
Tensile Strength, Yield (MPa) 262-310 | Compressive Strength (MPa) 448 | Hardness (Rockwell M) 110 | Flammability Rating UL94 HB | Glass Transition Temperature (°C) 140 |
Finishes
Garolite G-10 is typically a yellow/green material but is also sold in black. It does not take well to polishing due to its fibrous composition. Typically, polishing its matte surface finish will not buff out to a shine.
As Machined: Garolite G-10 generally has a smooth matte finish after machining. This means that parts left in their as-machined state won’t compromise the aesthetic appeal.
Bead Blast: Parts manufactured in G-10 can be bead blasted to remove any uneven surfaces produced during machining.

Cost-saving Design Tips
Garolite G-10 is a high-cost engineering plastic and as such, it is important to limit manufacturing costs where possible.
Design to standard stock sizes: Garolite G-10 is limited to bar, rod, tube, and sheet stock. When designing parts out of this material, take care to first learn the available stock sizes, then design to meet those constraints. Less material removed to achieve the final dimensions means increased cost savings both in terms of wasted material and time spent machining. CNC machining in Garolite G-10 requires diamond or superalloy tooling, so it’s an expensive material to machine.
