G10 Machining Services

DEK's G10 machining service produces insulators, cryogenic supports, fixtures and knife handles from Garolite G-10, holding ±0.01 mm. Diamond tooling and dust extraction tame its abrasive glass fibers.

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±0.01 mm
Tolerance Capability
3–5 days
Prototype Lead Time
No MOQ
1 to 10,000+ Pieces

Machined plastic block with precision holes on white

ISO 9001:2015 Certified AS9100D and ISO 13485 certified

What Is Garolite Machining and Why Use G10?

G10 is a glass-epoxy laminate that combines the stiffness of a fiber composite with near-zero moisture absorption and dielectric strength above 20 kV/mm. That is why it sits inside transformers, superconducting magnets and high-voltage test rigs.

The glass fibers that give it strength also destroy ordinary tooling, generate abrasive dust and delaminate at unsupported edges. We machine it on the same mills as your metal parts, as one of the laminates in our plastic CNC machining services. See all polymers under CNC machining plastics.

Laminates machined beside metals since 2002
ISO 9001:2015, ISO 13485 and AS9100D
Engineer-reviewed quote within 6 hours
IQC, IPQC, FAI and OQC on CMM and gauges

Hand holding a machined G10 plastic part

G10 Grades We Machine

From general-purpose G-10 to cryogenic and high-temperature laminates, each grade is selected for its electrical, thermal or visual role.

G-10 (NEMA grade)
Dielectric strength 20 kV/mm
The general-purpose, non-flame-retardant glass-epoxy laminate for insulators, fixtures and handles, in natural yellow-green and black.
FR-4
UL 94 V-0
The flame-retardant version, specified for anything near electrical equipment. See our FR4 machining page.
G-10 CR
4 K service
Cryogenic grade with controlled resin and fiber lay-up for structural insulators in magnets, dewars and detectors.
G-11 / FR-5
Rated to 155–180 °C
Higher-temperature laminates for parts that exceed the 130 °C max continuous service temperature of standard G-10.
Multi-layer G10 sheet
Black, olive, orange, blue
Colored and multi-layer G10 sheet in layered stacks for knife handles, grips and tool scales with a distinctive edge pattern.
G-10 laminate
275 MPa tensile (lengthwise)
Typical density 1.80–1.85 g/cm³, 240 MPa crosswise, water absorption 0.10–0.20% (24 h) and in-plane CTE of 10–13 × 10⁻⁶/K.

CNC milling G10 Garolite with diamond tooling and dust extraction

±0.01 mm
Features under 100 mm
±0.02 mm
Long thin plates
Ra 1.6–3.2
As-machined finish (µm)
0.5 mm
Minimum sheet thickness

G-10 CNC Machining Capabilities at DEK

We machine G10 on the same 3-, 4- and 5-axis mills as your metal parts, with PCD tooling and dust extraction at the spindle.

1

CNC Milling

3-, 4- and 5-axis CNC milling for insulator plates, fixture bases, spacers, brackets and handle scales, holding ±0.01 mm on features under 100 mm.
2

CNC Turning

CNC turning for bushings, standoffs, coil forms and cryogenic support rods machined from G10 rod and tube stock.
3

Drilling and Profiling

Drilling, reaming and profiling with PCD drills, backing plates and compression routers that stop breakout on thin sheet from 0.5 mm.
4

Sealing and Assembly

Epoxy edge sealing for cryogenic and vacuum parts, ultrasonic cleaning to remove glass dust, and assembly of insulator stacks with machined metal hardware.

Design & Machining Tips for G10

Key factors our engineers evaluate when machining abrasive glass-epoxy laminate to tight tolerances.

1

Abrasive Fibers and Tooling

G10 wears high-speed steel within minutes and carbide within a few parts. We run PCD and diamond-coated end mills and drills and price tool consumption into the quote.
2

Dust Extraction

G10 dust is a respiratory hazard and abrasive to machine ways. We cut with vacuum extraction at the spindle or filtered flood coolant, and clean machines after every run.
3

Delamination Avoidance

Plies separate at exit edges and around holes under a dull tool. We use compression routers, backing plates, climb milling on final passes and a 0.3 mm chamfer on all edges.
4

Thermal Expansion

In-plane expansion (10–13 µm/m·K) is close to steel, so G10 fixtures pair well with steel hardware; through-thickness is six times higher, so tolerance stack heights loosely.
5

Corners and Thin Walls

Specify 0.5 mm internal radii and avoid knife edges thinner than 1 mm. Walls need 1.0 mm minimum, 1.5 mm on parts over 100 mm long, or the fiber ends fray.
6

Holes and Threads

Tapped threads hold moderate loads; use inserts or through-bolts for cyclic loads, and oversize clearance holes by 0.1 mm. Flatness is 0.05 mm per 100 mm on plates over 5 mm thick.

When to Choose G10 vs FR4, PEI or Aluminum

The g10 fr4 difference comes down to flame retardancy; Ultem and aluminum trade insulation for precision or strength. More detail in our FR4 and G10 machining guide.

Criteria	This MaterialG10	FR4	Ultem (PEI)	Aluminum
Choose it for	Cryogenic work	Electrical gear	Precision sockets	Strength
Flame retardant	No	UL 94 V-0	–	–
Max temp	130 °C	–	170 °C	–
Insulates	Yes	Yes	–	No, conducts
Tolerances	±0.01 mm	Same as G10	Tighter	Tighter
Cost	Cheaper	Higher	Higher	–

Where G10 Machined Parts Are Used

From transformer insulators to MRI cryogenic supports and knife handles, G10 goes where metal would short, conduct heat or disturb a field.

Finishing Options for G10 Parts

G10 parts ship as CNC machining plus a finish suited to laminates; anodizing, plating and vapor polishing do not apply to G10.

G10 Finishes

As-machined
Bead blasting
Edge sealing
Painting
Laser marking

Need a finish not listed here? Ask our engineers for a review.

G10 Machining FAQs

Common questions from engineers specifying Garolite G-10 parts.

Is G10 hard to machine?

Yes, compared with thermoplastics. The glass fibers abrade cutting tools, the dust is hazardous and edges delaminate under poor tooling. With PCD tooling, dust extraction and backing plates, fiberglass laminate machining is accurate and G10 holds ±0.01 mm.

What is the difference between G10 and FR4?

Both are glass-epoxy laminates with nearly identical strength and dielectric properties. FR4 contains a flame retardant to meet UL 94 V-0; G10 does not. Specify FR4 near electrical equipment and G10 for cryogenic, handle and general fixture work.

Can G10 be used at cryogenic temperatures?

Yes. G-10 CR grade is a standard structural insulator at 4 K in superconducting magnets, MRI systems and research dewars because it keeps its strength and stays a thermal insulator. Edges are usually epoxy-sealed for vacuum service.

What tolerance can you hold in garolite machining?

±0.01 mm on features under 100 mm and ±0.02 mm on long thin plates, inspected at 23 °C. In-plane thermal expansion is close to steel, so G10 fixtures stay aligned with steel hardware.