How To Choose G10 Sheet Thickness?

Thickness decides how a G10 part performs after cutting, drilling, assembly, and long-term use. For buyers ordering a g10 glass epoxy sheet, the right thickness should not be selected only from a catalog range. It should match insulation distance, mechanical support, machining tolerance, screw position, working temperature, and the final product structure.

SENKEDA manufactures G10 sheets for electrical insulation, mechanical parts, tooling plates, fixtures, terminal boards, and CNC components. Before confirming an order, our team usually reviews the application first, then suggests a practical thickness range that can balance performance, processing cost, and production stability.

1. Confirm Whether The Sheet Mainly Insulates Or Supports

For insulation barriers, spacers, thin washers, and electrical separator parts, thinner sheets are often enough. Common thicknesses such as 0.5 mm, 1 mm, 1.5 mm, and 2 mm are easier to cut and suitable for parts that mainly need electrical separation.

For support plates, mounting boards, positioning blocks, and machined components, the sheet must resist bending and pressure. Thicknesses from 3 mm to 10 mm are often selected because they provide stronger rigidity while still keeping machining cost under control.

For heavy-duty fixtures, mold insulation plates, and load-bearing blocks, thicker options such as 12 mm, 20 mm, 30 mm, or above may be needed. These parts usually require better flatness control, slower machining speed, and clearer tolerance requirements.

2. Use Load Direction To Judge Thickness

G10 is reinforced by woven glass cloth and epoxy resin, so it has much higher strength than many general plastic sheets. According to data commonly referenced from IEC 60893 and NEMA LI 1 material classifications, standard G10 laminate can often reach flexural strength above 300 MPa, while density usually stays around 1.8 to 2.0 g/cm³.

This data helps buyers understand why thickness should follow the stress direction. If a part only separates two surfaces, thin material may be suitable. If the part is clamped, screwed, suspended, or exposed to vibration, a thicker sheet can reduce bending and cracking risk.

3. Match Thickness With Electrical Safety Margin

Electrical insulation design should consider working voltage, creepage distance, clearance, edge condition, and surface cleanliness. ASTM D149 is often used to evaluate dielectric breakdown strength. Many G10 sheets can show dielectric strength around 10 to 20 kV/mm under controlled laboratory conditions, but real parts may perform differently after drilling, milling, or long-term exposure to humidity.

For high-voltage assemblies, buyers should avoid selecting the thinnest possible sheet only to save cost. Extra thickness can provide more safety margin, especially for parts placed near coils, busbars, terminals, or metal frames. This is one of the most important steps in G10 sheet thickness selection.

4. Check Machining Method Before Bulk Cutting

Different thicknesses create different machining behavior. Thin sheets may vibrate during cutting, so clamping method and blade sharpness matter. Medium sheets are usually easier for CNC routing, drilling, and contour cutting. Thick sheets need more stable equipment, slower feed speed, and better dust control.

Tolerance also changes the cost. A simple insulation plate may accept standard tolerance. A stacked component, positioning spacer, sliding part, or fixture block may need tighter grinding or finishing. Setting tolerance too strictly can increase waste, inspection time, and delivery pressure.

5. Think About Screw Holes And Edge Distance

Many G10 parts fail not because the raw sheet is weak, but because the hole design is too close to the edge. When screws, rivets, slots, or countersunk holes are required, the thickness must support the fastening force.

For small washers and light covers, thin sheets may work well. For parts that need repeated assembly, the sheet should be thick enough to prevent hole deformation. SENKEDA can review hole diameter, edge distance, and drawing structure before production, helping customers reduce cracking risk during installation.

6. Balance Material Cost With Long-Term Use

Thicker sheets consume more material, increase shipping weight, and require longer machining time. They may also cause more tool wear during drilling or milling. That is why a practical thickness should solve the application problem without adding unnecessary cost.

For repeat orders, standard sheet size and cutting layout also matter. Better nesting can improve material yield and reduce offcuts. As a bulk G10 sheet supplier, we often suggest reviewing finished part dimensions together with sheet size before confirming volume production.

7. Review The Working Environment

Humidity, heat, oil contact, cleaning chemicals, and vibration can affect long-term part performance. ASTM D570 is widely used to evaluate water absorption of insulating materials. G10 usually has low water absorption, but machined edges and drilled holes should still be kept clean for electrical applications.

For humid electrical cabinets, edge finishing and surface cleaning are important. For hot equipment areas, thickness should be checked together with compression force and heat exposure. For moving equipment, vibration resistance and screw design may be more important than simply increasing thickness.

Final Thickness Decision

A reliable thickness decision comes from matching the drawing with real working conditions. Buyers should confirm voltage level, load type, machining process, tolerance, hole design, sheet size, and order quantity before production.

SENKEDA can support standard sheets, cut-to-size panels, CNC machined parts, drilled insulation boards, and sample testing before batch orders. Correct thickness helps reduce waste, improve assembly stability, and make future purchasing easier to repeat.