China has a well-developed supply chain for epoxy fiberglass laminates used in electrical insulation, electronics, machinery, fixtures, molds, battery systems and industrial equipment. Buyers can source standard G10 sheets, flame-retardant FR4 sheets, high-temperature G11 sheets, anti-static laminates, copper-clad boards and CNC-machined insulation components from manufacturers across Guangdong, Jiangsu, Zhejiang, Jiangxi, Henan and Shaanxi.

For international procurement teams, supplier selection should not be based on price alone. G10 sheet quality depends on the glass cloth structure, epoxy resin formulation, curing process, thickness tolerance, flatness, internal bonding strength and electrical performance.

A sheet may look similar on the surface but behave very differently during drilling, milling, high-voltage use, humidity exposure or long-term thermal cycling. The most reliable suppliers are those able to provide stable material properties, traceable quality records, clear technical documentation and responsive support for custom requirements.

G10 Sheet Manufacturing Process

How to Evaluate a G10 Sheet Manufacturer

A professional G10 sheet supplier should be evaluated through a combination of manufacturing capability, material knowledge, quality control and commercial reliability.

Key evaluation factors include:

- Factory production capability and consistency of raw material supply.

- Experience with epoxy glass laminate grades such as G10, FR4, G11, FR5 and 3240.

- Availability of technical data sheets and batch inspection reports.

- Thickness tolerance, flatness control and sheet-size consistency.

- Ability to support custom sheet sizes, colors, thicknesses and CNC machining.

- Experience with export packaging, palletizing and international shipping documents.

- Certification readiness for ISO management systems, RoHS, REACH and flame-retardant requirements.

- Stable delivery lead times for standard and customized orders.

- Clear communication during sampling, production and inspection stages.

Buyers should also understand that G10 and FR4 are not automatically interchangeable.

G10 is a glass-cloth-reinforced epoxy laminate widely used for electrical insulation, structural components, machined parts, fixtures and industrial equipment. FR4 is a related glass epoxy laminate with flame-retardant properties. G11 is typically selected for higher-temperature applications where better thermal resistance is required.

The purchase specification should always identify the exact grade, thickness, sheet dimensions, tolerance, required performance values and intended application.

G10 FR4 G11 Material Comparison

Top 10 G10 Sheet Manufacturers in China

Manufacturer	Location	Main Product Focus	Custom Manufacturing Capability	Suitable Buyer Type
Guangdong Weishi New Materials Co., Ltd.	Guangdong	G10, FR4, G11, epoxy fiberglass sheets, anti-static sheets	Custom sheets, cut parts, OEM/ODM and machining support	SMEs, equipment makers and industrial OEMs
Zhejiang Jingjing Insulation Materials Co., Ltd.	Zhejiang	FR4, epoxy sheets, phenolic sheets and insulation laminates	Sheet sizing and insulation-material supply	Multi-material industrial buyers
Guangzhou Shengrui Insulation Materials Co., Ltd.	Guangdong	G10, FR4, G11, FR5, ESD materials and CNC products	Multi-color sheets, CNC parts and custom materials	Fixture, electronics and machining buyers
Jiujiang Xinxing Fiberglass Material Co., Ltd.	Jiangxi	Fiberglass laminates and composite materials	Composite-material supply and custom projects	Buyers focused on fiberglass-reinforced materials
Jiujiang Xinrui Composite Co., Ltd.	Jiangxi	G10 sheets and industrial composite materials	Industrial-grade custom composites	Tooling and fixture manufacturers
Henan Jinzhi Electrical Insulation New Material Co., Ltd.	Henan	Electrical insulation materials	Sheet supply and insulation-material projects	Electrical equipment and transformer buyers
J&Q New Composite Materials Company	Shaanxi	FR4, G10, 3240, Bakelite and engineering plastics	Material selection and custom supply	Buyers requiring multiple industrial materials
ZTelec Group	China	G10, FR4, G11 and electrical laminated sheets	Customized electrical laminate sheets	Standard-driven electrical projects
Hongda / JHD Material	China	G10, FR4, 3240 and phenolic laminates	Standard sheet supply and cut sizes	Buyers purchasing conventional laminate grades
Guangdong Yinuo Technology Co., Ltd.	Guangdong	FR4, G11, FRP sheets and copper-clad laminates	FRP panels, laminate materials and OEM supply	Industrial OEMs and composite-material buyers

1. Guangdong Weishi New Materials Co., Ltd.

Guangdong Weishi New Materials Co., Ltd. is a manufacturer focused on high-performance epoxy insulation boards and composite materials. Its main product range includes FR4 fiberglass sheets, G10 sheets, G11 sheets, epoxy resin sheets, anti-static insulation sheets, copper-clad laminates and related engineering materials.

The company is well suited to buyers looking for a flexible manufacturer that can support both standard material purchasing and customized project requirements. Rather than focusing only on high-volume catalog orders, Guangdong Weishi is positioned to work with small and medium-sized industrial brands, equipment manufacturers, machining companies and overseas distributors that require more responsive communication and customized support.

Its advantages include:

- Broad product coverage across G10, FR4, G11 and epoxy fiberglass insulation materials.

- Support for customized thicknesses, sheet dimensions, colors and cut-to-size requirements.

- Practical support for buyers requiring materials for CNC machining, drilling, routing and custom component production.

- Flexible cooperation for sample evaluation, pilot orders and repeat purchasing programs.

- Guangdong-based production and export communication advantages for electronics, electrical equipment and machinery customers.

- Ability to support OEM and ODM projects involving insulation components, industrial parts and customer-specific packaging requirements.

Guangdong Weishi is particularly relevant for buyers that need a supplier able to discuss the application, not simply quote a standard sheet. For example, a customer manufacturing battery pack insulation parts may need controlled thickness, machining stability, moisture resistance, electrical insulation and reliable export packaging. A supplier that understands the full use case can help reduce production risks before the customer moves to volume orders.

2. Zhejiang Jingjing Insulation Materials Co., Ltd.

Zhejiang Jingjing Insulation Materials Co., Ltd. supplies a range of electrical insulation materials, including fiberglass sheets, FR4 sheets, epoxy sheets, phenolic sheets and laminated products.

The company is relevant for procurement teams that need to compare several insulation materials within one sourcing project. Buyers can evaluate epoxy glass laminates alongside phenolic laminates and other electrical insulation grades based on the actual mechanical, thermal and electrical requirements of the application.

Its main strengths include:

- Product coverage across multiple industrial insulation categories.

- Potential suitability for electrical, machinery and industrial-equipment applications.

- Ability to support buyers sourcing several laminate grades at the same time.

- Zhejiang location within an established industrial-material supply network.

This supplier type may be suitable for distributors, panel builders, electrical-equipment producers and purchasing teams that want to consolidate several insulation-material categories through one supplier relationship.

3. Guangzhou Shengrui Insulation Materials Co., Ltd.

Guangzhou Shengrui Insulation Materials Co., Ltd. offers a broad selection of glass epoxy laminate products, including G10, FR4, G11, FR5, ESD FR4/G10, 3240 sheets, copper-clad laminates, prepregs and CNC-machined components.

The company is especially relevant to customers requiring specialty grades or secondary processing. Its product range may support applications such as electronic test fixtures, PCB assembly tooling, electrical insulation components, custom machine parts, knife-handle materials and industrial jigs.

Its strengths include:

- Product range covering conventional and specialty epoxy laminate grades.

- Availability of anti-static materials for electronics-related applications.

- Multi-color G10 sheet options for industrial, tooling and decorative applications.

- CNC processing support for customers requiring finished components.

- Experience with projects that combine material selection and downstream machining.

Buyers should confirm the target electrical, mechanical and thermal properties for each grade, particularly when requesting ESD, high-temperature or flame-retardant materials.

4. Jiujiang Xinxing Fiberglass Material Co., Ltd.

Jiujiang Xinxing Fiberglass Material Co., Ltd. is relevant for buyers sourcing fiberglass-reinforced composite materials and glass epoxy laminates.

Jiangxi has strong links to the fiberglass supply chain, making suppliers in this region potentially suitable for customers that prioritize reinforcement quality, glass-cloth structure and laminate consistency.

Its possible strengths include:

- Fiberglass-material specialization.

- Suitability for buyers focused on glass-reinforced epoxy laminate performance.

- Potential support for custom composite-material projects.

- Relevance to industrial equipment, electrical insulation and structural composite applications.

When evaluating a fiberglass laminate supplier, buyers should ask about the glass fabric type, resin content, laminate density, thickness consistency and internal bonding quality.

5. Jiujiang Xinrui Composite Co., Ltd.

Jiujiang Xinrui Composite Co., Ltd. supplies G10-related materials and industrial composite products. It may be relevant for projects involving high-temperature fixtures, soldering-process support materials, industrial tooling and composite components.

This type of supplier can be useful for electronics manufacturing and machinery customers that need materials with good machinability, dimensional stability and mechanical performance.

Key areas to discuss include:

- Thermal stability during repeated processing cycles.

- Flatness after machining.

- Moisture absorption performance.

- Delamination resistance.

- Edge quality after drilling, routing and countersinking.

- Suitability for wave-soldering fixtures or electronic assembly tooling.

For fixture applications, buyers should send the actual operating temperature, contact conditions, machining drawings and expected service life before requesting a quotation.

6. Henan Jinzhi Electrical Insulation New Material Co., Ltd.

Henan Jinzhi Electrical Insulation New Material Co., Ltd. is positioned in the electrical insulation material sector. It may be suitable for buyers serving transformer, motor, switchgear, electrical-control and high-voltage equipment applications.

For electrical insulation projects, material selection should be based on more than mechanical strength. The supplier should be able to discuss dielectric strength, insulation resistance, humidity resistance, thermal class and long-term performance under electrical load.

Relevant qualification questions include:

- What dielectric strength values are available for the proposed thickness?

- Is the test performed perpendicular or parallel to the laminate?

- What are the insulation-resistance values after humidity exposure?

- What thermal class is recommended for the application?

- Can the supplier provide batch-specific test documentation?

- Is the sheet suitable for cutting, drilling and punching without delamination?

This supplier type may be particularly useful for buyers that need electrical insulation materials for equipment manufacturing rather than general-purpose machining materials.

7. J&Q New Composite Materials Company

J&Q New Composite Materials Company offers FR4 epoxy sheets, G10 sheets, 3240 epoxy sheets, Bakelite, phenolic cotton sheets and engineering plastics.

Its broad material range makes it suitable for buyers comparing multiple options for industrial components. In some cases, G10 or FR4 may not be the most cost-effective material. For lower-temperature or lower-voltage applications, phenolic sheet or engineering plastic may meet the functional requirement at a lower overall material cost.

Key strengths include:

- Multiple insulation-material options under one sourcing project.

- Ability to compare G10, FR4, 3240, phenolic sheet and engineering plastics.

- Potential fit for distributors and purchasing teams handling varied industrial-material requirements.

- Suitable for applications where material substitution must be technically evaluated.

Buyers should ensure that cost reduction does not lead to unintended material substitution. Any alternative must be approved against the required electrical, thermal, mechanical and chemical properties.

8. ZTelec Group

ZTelec Group supplies electrical laminated sheets, including G10, FR4 and G11 grades. It is suitable for buyers with formal technical specifications and a strong focus on electrical insulation performance.

G10, FR4 and G11 materials are often selected according to standards and application conditions. Buyers working with switchgear, motors, transformers, electrical panels, high-voltage equipment and related industrial systems should clearly define the required standard and test method.

Typical areas to verify include:

- Material grade and equivalent designation.

- Applicable electrical insulation standard.

- Thickness and sheet-size tolerance.

- Mechanical properties.

- Dielectric performance.

- Thermal resistance.

- Moisture absorption.

- Flame-retardant requirements.

- Batch identification and traceability.

This supplier type can be relevant for engineering-led procurement teams that require materials to align with formal internal specifications.

9. Hongda / JHD Material

Hongda, represented through JHD Material, supplies G10 epoxy glass laminates, FR4 sheets, 3240 epoxy sheets and phenolic cotton sheets.

This supplier may be suitable for buyers with established material specifications who require conventional epoxy laminate grades in standard formats. It can also be relevant for industrial distributors and machine shops purchasing G10 or FR4 sheets for downstream cutting and fabrication.

Potential strengths include:

- Focus on commonly used electrical insulation laminate grades.

- Relevant product range for conventional industrial applications.

- Suitability for buyers comparing G10, FR4 and phenolic alternatives.

- Potential support for standard sheet and cut-size purchasing.

Buyers should confirm whether the material offered is actual G10, flame-retardant FR4 or another epoxy fiberglass grade. The product name alone is not enough to confirm performance.

10. Guangdong Yinuo Technology Co., Ltd.

Guangdong Yinuo Technology Co., Ltd. offers FRP sheets, FRP panels, GRP sheets, fiberglass materials, FR4, G11, G11-H, EPGM203 and copper-clad laminated materials.

The company may be suitable for buyers with broader composite-material needs, especially projects that combine electrical insulation sheets with FRP panels or structural composite components.

Its relevant strengths include:

- Wide product range covering FRP sheets and electrical laminate materials.

- Potential support for industrial panels, insulation boards and composite projects.

- Guangdong location suitable for export-oriented customers.

- Relevance for OEM projects requiring multiple composite-material categories.

For industrial buyers, the value of a broader supplier may be the ability to coordinate multiple materials through one project team. However, each material should still be tested independently against the final application requirements.

G10 Sheet Manufacturer Comparison

Manufacturer	Product Range	Customization Level	MOQ Flexibility	Recommended Verification Focus
Guangdong Weishi	G10, FR4, G11, anti-static and epoxy sheets	High	Flexible by project	Material grade, machining samples, batch consistency
Zhejiang Jingjing	FR4, epoxy, phenolic and laminated sheets	Medium	Confirm by product	Grade selection, sheet tolerance and delivery schedule
Guangzhou Shengrui	G10, FR4, G11, FR5, ESD and CNC products	High	Project-based	ESD values, flame rating and machining tolerances
Jiujiang Xinxing	Fiberglass laminates and composites	Medium	Confirm by project	Glass cloth, resin content and internal bonding
Jiujiang Xinrui	G10 and industrial composites	Medium	Confirm by project	Thermal stability and machinability
Henan Jinzhi	Electrical insulation materials	Medium	Confirm by project	Dielectric properties and humidity performance
J&Q New Composite	G10, FR4, 3240, Bakelite and plastics	Medium	Confirm by product	Certificate scope and alternative-material suitability
ZTelec Group	G10, FR4, G11 electrical laminates	Medium	Confirm by project	Standards, test methods and batch traceability
Hongda / JHD	G10, FR4, 3240 and phenolic sheets	Medium	Confirm by product	Actual grade and performance documentation
Guangdong Yinuo	FR4, G11, FRP and copper-clad materials	High	Project-based	Certification validity and material-specific testing

Common Risks When Buying G10 Sheets

Confusing G10 with FR4

One of the most common mistakes is assuming G10 and FR4 are exactly the same product. They may use similar glass cloth and epoxy resin systems, but FR4 is generally specified when flame-retardant performance is required.

Buyers should not use "G10/FR4" as a general purchase description unless both grades are acceptable for the application. The purchase order should clearly state the required material grade and performance criteria.

Surface Quality Hiding Internal Defects

A sheet can have a smooth green, yellow, black or natural surface while still containing internal quality problems.

Potential hidden defects include:

- Uneven glass-cloth distribution.

- Resin-rich or resin-starved zones.

- Internal voids.

- Incomplete impregnation.

- Weak interlayer bonding.

- Delamination after drilling or milling.

- Edge cracking during machining.

- Excessive internal stress that causes warping.

A useful internal inspection method is to machine a sample sheet before approving mass production. Drill holes, cut slots, mill edges and countersink several locations. Then inspect the cut edges for voids, dry fiber, layer separation, cracking and inconsistent resin distribution.

This is often more revealing than a visual inspection of the finished sheet surface.

Unclear Thickness Tolerance

A nominal 10 mm G10 sheet may not be exactly 10.00 mm. Thickness tolerance varies according to the supplier, production process, sanding method and order specification.

For precision machining projects, buyers should define:

- Nominal thickness.

- Minimum and maximum acceptable thickness.

- Flatness requirement.

- Sheet-length and sheet-width tolerance.

- Surface-finish requirement.

- Measurement method.

- Inspection sampling plan.

Without a written tolerance agreement, suppliers may apply their own standard range, which may not fit precision assembly requirements.

Incomplete Compliance Documentation

RoHS, REACH, ISO management certificates and flame-retardant reports are different documents with different purposes.

- RoHS relates to restricted substances.

- REACH relates to chemical substance compliance.

- ISO certification relates to management systems.

- UL 94 relates to flammability behavior.

- Material test reports relate to the actual performance of a specific product or batch.

Buyers should request the relevant documents for their target market and application rather than accepting a single generic certificate.

Sample Quality Not Matching Production Quality

A supplier may send a hand-selected sample that does not represent future production quality. This can happen when the sample comes from a different raw-material batch, press cycle or production line.

To reduce this risk, use a three-stage approval process:

Stage	Main Purpose	Recommended Buyer Action
Initial material sample	Confirm basic appearance and material grade	Check thickness, color, density, surface and technical data
Machining sample	Confirm processing performance	Drill, mill, route and inspect cut edges
Pilot production order	Confirm repeatability	Compare several sheets, test key properties and inspect packaging

For critical applications, keep an approved reference sample and use it for future incoming-quality comparisons.

G10 Sheet Quality Inspection

Buyer's Guide for G10 Sheet Procurement

Define Your Material Requirement

Before sending inquiries, prepare a detailed product specification.

Include:

- Material grade: G10, FR4, G11, FR5 or other required grade.

- Sheet thickness.

- Thickness tolerance.

- Sheet length and width.

- Flatness requirement.

- Color requirement.

- Electrical insulation requirement.

- Flame-retardant requirement.

- Operating temperature range.

- Moisture or humidity exposure conditions.

- Mechanical load requirement.

- Machining process.

- Annual quantity forecast.

- Sample quantity.

- Packaging requirement.

- Destination port or delivery address.

A precise specification reduces misunderstandings and allows suppliers to quote the correct material from the beginning.

Request Technical Documents

Before ordering, request the following documents:

- Product technical data sheet.

- Material composition or grade statement.

- Thickness tolerance specification.

- Mechanical-property test report.

- Electrical-property test report.

- Water-absorption data.

- Flame-retardant documentation, if required.

- RoHS declaration, if required.

- REACH declaration, if required.

- Quality-management certificate, if applicable.

- Batch inspection report or certificate of analysis.

- Packaging photos or packing specification.

The best approach is to evaluate the documents together with a physical sample rather than relying on paperwork alone.

Confirm Factory Capability

A supplier may be a manufacturer, distributor, converter or trading company. Each type can be suitable, but buyers should know which one they are working with.

Questions to ask include:

- Are the sheets laminated in-house?

- Which steps are completed internally?

- Is CNC machining performed in-house?

- Which raw materials are controlled directly by the factory?

- What is the normal production lead time?

- What is the backup plan for resin or glass-cloth shortages?

- Can the supplier provide production and inspection photos?

- Can the factory support third-party inspection?

- Can the supplier provide samples from the actual proposed production material?

Clear answers to these questions help buyers evaluate production control and supply stability.

Plan Shipping and Packaging

G10 sheets are durable, but they can be damaged by poor stacking, edge impact, surface scratching and moisture during long-distance transport.

Packaging should be designed around the sheet size, thickness and shipping method.

Recommended requirements include:

- Protective surface film or interleaving paper.

- Edge protectors and reinforced corners.

- Export-grade pallets.

- Moisture-resistant outer packaging.

- Stable strapping suitable for container loading.

- Clear pallet labels.

- Sheet quantity and gross-weight marking.

- Batch identification.

- Packing list matching the physical pallet count.

For LCL shipments, reinforced edge protection is particularly important because goods may be handled several times between factory pickup and destination delivery.

Custom G10 Sheet Applications

Conclusion

China provides a broad range of G10 sheet, FR4 sheet, G11 sheet and epoxy fiberglass laminate suppliers for global industrial buyers. The most suitable manufacturer depends on the required material grade, application conditions, production volume, custom-processing needs and documentation requirements.

Successful purchasing begins with a precise specification and a structured qualification process. Buyers should compare technical data, request representative samples, perform machining tests, verify compliance documents and use pilot orders to confirm consistency before scaling production.

For buyers seeking flexible custom support, responsive communication and practical experience with epoxy fiberglass insulation materials, Guangdong Weishi New Materials Co., Ltd. is a manufacturer worth including in the supplier evaluation process. Its product coverage across G10, FR4, G11 and related composite insulation materials makes it suitable for projects that require standard sheets, custom sizes, machined parts or OEM-oriented material solutions.

Frequently Asked Questions

1. Is G10 sheet suitable for high-voltage electrical insulation?

G10 can be used in many electrical insulation applications because of its glass-fiber reinforcement, epoxy resin structure and good dielectric properties. However, suitability depends on the operating voltage, thickness, humidity level, temperature, creepage distance, clearance distance and applicable safety requirements. Buyers should confirm the required dielectric strength and insulation resistance for the actual application.

2. How do I verify whether a supplier's ISO certificate is still valid?

Request the complete certificate, including the legal company name, address, certificate number, issue date, expiry date, certification body and scope. Verify the certificate through the certification body's official database or by contacting the certification body directly. Confirm that the certificate scope covers manufacturing activities relevant to epoxy insulation materials.

3. What is the difference between G10, FR4 and G11?

G10 is a glass-cloth-reinforced epoxy laminate used for insulation and mechanical applications. FR4 is a similar epoxy glass laminate with flame-retardant characteristics. G11 is generally selected for applications requiring higher temperature resistance. The correct choice should be based on the required flame performance, operating temperature, electrical stress, humidity exposure and mechanical load.

4. What should I test before placing a bulk G10 sheet order?

Before a bulk order, test thickness consistency, flatness, surface quality, cut-edge quality, machinability, internal bonding, water absorption, dielectric performance and dimensional stability. If the sheet will be CNC machined, perform drilling, routing, milling and countersinking tests on the production sample.

5. Why does G10 sheet delaminate during drilling or milling?

Delamination may be caused by weak internal bonding, inconsistent resin impregnation, voids, unsuitable cutting tools, excessive cutting heat, poor machining parameters or stress within the laminate. Buyers should inspect machined sample edges and use appropriate cutting tools, feed rates and cooling methods.