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T300, T700, and T800 are three widely recognized carbon fiber grades used in composite materials. Although all three can be converted into carbon fiber fabric, prepreg, unidirectional reinforcement, and other composite forms, their mechanical properties and suitable applications are different.
For buyers of carbon fiber cloth, the fiber grade is only one part of material selection. Tow size, fabric weight, weave structure, resin system, processing method, laminate design, and cost should also be considered.
This guide compares T300 vs T700 vs T800 carbon fiber and explains how differences in tensile strength, tensile modulus, elongation, and processing requirements affect the selection of carbon fiber fabric for industrial and high-performance composite applications.
T300, T700, and T800 are PAN-based carbon fiber grades originally developed by Toray. These designations are widely recognized in the composites industry as reference points for different levels of carbon fiber performance.
In general, T300 is a standard-modulus carbon fiber with reliable mechanical performance and broad industrial use. T700 provides substantially higher tensile strength while maintaining a similar modulus range. T800 belongs to a higher-performance class and provides both higher tensile strength and higher modulus.
It is important to note that T300, T700, and T800 refer to specific fiber grades rather than generic carbon fiber categories. Other carbon fiber manufacturers may offer comparable fibers under different grade names and specifications.
When sourcing T300 carbon fiber fabric, T700 carbon fiber fabric, or T800 carbon fiber fabric, buyers should therefore confirm the actual fiber grade, tow size, fabric construction, and technical data rather than relying only on a general performance description.
The main differences between these carbon fiber grades can be seen in tensile strength, tensile modulus, and elongation.
Property | T300 | T700S | T800S |
Tensile Strength | Approx. 3,530 MPa | Approx. 4,900 MPa | Approx. 5,880 MPa |
Tensile Modulus | Approx. 230 GPa | Approx. 230 GPa | Approx. 294 GPa |
Elongation at Break | Approx. 1.5% | Approx. 2.1% | Approx. 2.0% |
Fiber Type | PAN-based | PAN-based | PAN-based |
General Positioning | Standard performance | High strength | Higher strength and modulus |
These figures are useful for understanding the relative performance of the fibers, but they should not be interpreted as guaranteed properties of a finished carbon fiber fabric or composite laminate.
Fabric architecture, fiber volume fraction, resin system, curing conditions, manufacturing defects, and laminate design all influence final composite performance.
T300 is one of the most established carbon fiber grades in the composites industry.
Its combination of approximately 3.5 GPa tensile strength and 230 GPa tensile modulus provides a practical balance between mechanical performance, processability, availability, and cost.
T300 carbon fiber can be converted into woven fabric, unidirectional reinforcement, multiaxial fabric, prepreg, and carbon fiber composite products.
T300-grade or similar standard-performance carbon fibers can be suitable for applications where carbon fiber is required primarily for weight reduction, stiffness, and structural reinforcement without requiring the highest possible fiber strength.
Typical applications can include industrial components, sporting goods, automotive parts, marine components, reinforcement panels, and general composite structures.
For many commercial applications, moving to a more expensive carbon fiber does not automatically improve the finished product enough to justify the additional material cost.
T700 is particularly interesting because its tensile modulus remains around the same general level as T300, while its tensile strength is considerably higher.
This illustrates an important principle in carbon fiber selection: higher tensile strength does not necessarily mean proportionally higher stiffness.
T700 is therefore commonly considered when a structure requires higher strength while maintaining the characteristics of a standard-modulus carbon fiber.
A T700 carbon fiber fabric can be considered when the design requires higher tensile performance than conventional T300-based reinforcement.
Typical applications can include UAV and drone structures, high-performance sporting goods, lightweight structural components, automotive composite parts, marine structures, and industrial structural reinforcement.
However, the benefits of T700 can only be fully utilized when the complete composite laminate is properly designed. Using T700 fiber in a poorly designed laminate does not automatically produce a high-performance composite component.
T800 represents another step toward higher mechanical performance.
Compared with T300 and T700, T800 provides both higher tensile strength and a higher tensile modulus. This makes it attractive for structures where weight efficiency and mechanical performance are particularly important.
T800-based carbon fiber materials are more likely to be considered for demanding aerospace, UAV, sporting, and advanced structural composite applications.
At the fiber level, T800 offers higher mechanical properties than T300 and T700. At the component level, however, material selection is more complicated.
A composite designer must consider required load direction, laminate thickness, fiber orientation, resin compatibility, fiber volume fraction, impact requirements, manufacturing process, quality control, and cost target.
For this reason, T800 is not automatically the best choice for every carbon fiber component.
The most important difference between T300 and T700 is tensile strength.
Their tensile modulus is relatively similar, while T700 provides significantly higher tensile strength. This means that if an application is limited primarily by fiber tensile strength, T700 may offer an advantage.
If the design is stiffness-driven, however, simply changing from T300 to T700 may not create the improvement a buyer expects.
Tensile strength describes how much tensile stress a material can withstand before failure.
Tensile modulus describes the material's resistance to elastic deformation.
Therefore, when evaluating T300 vs T700 carbon fiber, buyers should determine whether the component requires higher strength, higher stiffness, lower weight, better fatigue performance, a specific laminate thickness, or a combination of these requirements.
Two carbon fiber fabrics with similar GSM and weave patterns can use different carbon fiber grades and therefore have different fiber-level mechanical properties.
At the same time, changing the fiber grade without considering the laminate design may not deliver the expected performance improvement.
This is why the fiber grade should always be evaluated together with fabric construction and the final application.
Compared with T700, T800 offers higher tensile strength together with higher modulus. This can provide additional design flexibility for performance-sensitive structures.
However, T800 generally belongs to a more demanding and higher-cost material category. For many industrial products, T700 or even T300 may already provide sufficient performance.
T800 becomes more relevant when the structure has strict requirements for weight reduction, strength-to-weight ratio, and stiffness-to-weight ratio.
For example, a cosmetic automotive panel and a structural UAV component may both use carbon fiber fabric, but their material requirements can be completely different.
A cosmetic automotive component may place more emphasis on surface appearance, twill weave pattern, resin clarity, and surface finish.
A structural UAV component may place greater emphasis on tensile strength, stiffness, fiber orientation, weight, and laminate efficiency.
Choosing T800 simply because its fiber properties are higher can increase material cost without creating a meaningful advantage in the finished part.
The correct carbon fiber grade should therefore be selected according to the actual mechanical and processing requirements of the component.
No. Fiber grade is important, but it is only one factor determining the quality and performance of carbon fiber fabric.
A high-quality fabric also depends on tow size, fabric weight, weave structure, fiber alignment, weaving quality, and manufacturing consistency.
Carbon fibers are grouped into bundles known as tows. Common tow sizes include 1K, 3K, 6K, 12K, and 24K.
Tow size influences fabric appearance, thickness, drape, productivity, and cost.
A 3K carbon fiber fabric and a 12K carbon fiber fabric can therefore behave differently even when made from fibers with similar mechanical properties.
Carbon fiber fabrics are available in a wide range of areal weights. Common commercial constructions include approximately 100–160 g/m², 200 g/m², 240–300 g/m², 400 g/m², and 600 g/m² or heavier.
Lower-GSM fabrics can be useful for lightweight laminates and fine layups, while heavier fabrics can build laminate thickness more quickly.
The most common woven carbon fiber fabric structures include plain weave and twill weave.
Plain weave provides frequent interlacing and good fabric stability. Twill weave generally offers better drape and a distinctive diagonal appearance.
The appropriate weave depends on part geometry, manufacturing method, appearance requirements, and laminate design.
Even when two fabrics use the same carbon fiber grade, differences can exist in fiber alignment, weaving tension, width tolerance, areal weight tolerance, tow distortion, broken fibers, fuzz, surface appearance, and roll-to-roll consistency.
A carbon fiber fabric should not be evaluated simply as “T700 fabric” or “T800 fabric.”
For purchasing and technical evaluation, the complete specification should include at least the fiber grade, tow size, fabric construction, GSM, width, thickness where applicable, and relevant tolerances.
This provides a much more meaningful basis for comparing carbon fiber cloth suppliers and alternative materials.
The correct selection starts with the application rather than the fiber grade name.
Determine whether the component is primarily strength-driven, stiffness-driven, or weight-driven.
If the existing design already meets its mechanical requirements using a standard-grade carbon fiber, upgrading to T700 or T800 may provide limited commercial benefit.
The application may require woven carbon fiber fabric, unidirectional carbon fiber fabric, multiaxial carbon fiber fabric, spread tow fabric, prepreg, or another reinforcement form.
Woven fabric provides multidirectional reinforcement and convenient handling, while unidirectional reinforcement concentrates fibers in a specific load direction.
Tow size and areal weight should match the required laminate construction and manufacturing process.
For example, lightweight UAV skins may require a different carbon fiber cloth construction from thick industrial structural laminates.
Carbon fiber reinforcements can be used in hand lay-up, vacuum bagging, vacuum infusion, resin transfer molding, prepreg/autoclave processing, and other composite manufacturing processes.
The selected carbon fiber fabric must have suitable handling, drape, and resin impregnation characteristics for the intended process.
The highest-performance fiber is not always the most economical solution.
For commercial composite manufacturing, a properly selected T300 or T700 fabric can sometimes provide a more practical solution than specifying T800 without a clear engineering requirement.
To obtain a more accurate material recommendation and quotation, buyers can provide the required fiber grade, tow size, GSM, weave structure, roll width, quantity, manufacturing process, and final application.
If an existing specification or TDS is available, it can also be used as a reference when evaluating an equivalent carbon fiber fabric.
UAV structures are a good example of why carbon fiber selection cannot be based on a single property.
Weight is critical, but different areas of an unmanned aircraft experience different loads.
Carbon fiber materials may be used for wing skins, fuselage structures, spars, frames, reinforcement parts, and sandwich panels.
A lightweight woven carbon fiber fabric may be selected for skins and complex shapes, while unidirectional carbon fiber can be used along major load paths.
T700 and other high-strength carbon fibers can be attractive where higher structural efficiency is required. More demanding designs may consider T800-class materials.
The final choice should be based on structural design rather than assuming one carbon fiber grade is universally suitable for UAVs.
For sandwich structures, carbon fiber skins can also be combined with lightweight core materials such as PMI foam, PVC foam, or other suitable structural cores depending on the design requirements.
Carbon fiber is used in performance-oriented marine structures where weight reduction and stiffness are important.
Possible applications include yacht structures, masts and booms, structural panels, bulkheads, deck components, and high-speed craft components.
In sandwich construction, carbon fiber fabric can be combined with structural core materials such as PVC foam or PET foam to produce lightweight composite panels.
The carbon fiber skins provide structural performance, while the core increases panel thickness and bending stiffness without adding excessive weight.
For marine applications, the carbon fiber grade should be selected together with laminate structure, resin system, core material, manufacturing process, and service conditions.
This system-level approach is generally more useful than selecting a carbon fiber solely because it has a higher tensile strength.
Yes. At the fiber level, T700S has substantially higher tensile strength than T300 while having a similar tensile modulus.
However, the strength of a finished composite laminate depends on additional factors such as fabric construction, resin, fiber volume fraction, and manufacturing quality.
T800S has higher nominal tensile strength and modulus than T700S.
Whether this produces a meaningful advantage in a finished component depends on structural design, laminate construction, and manufacturing process.
Not necessarily.
T300 and T700S have similar nominal tensile modulus values. T700's main advantage over T300 is its higher tensile strength.
This is why buyers should distinguish between carbon fiber strength and carbon fiber modulus.
Potentially, but replacement should not be based only on tensile strength.
Tow size, fabric construction, GSM, thickness, resin compatibility, processing requirements, and laminate design should also be checked.
For an existing composite specification, the replacement material should be evaluated against the required fabric and laminate properties.
Technically, T800 can provide higher fiber-level performance, but direct substitution is not always necessary or economical.
A proper material evaluation should be carried out before changing the fiber grade.
There is no single grade that is best for every application.
T300 can be suitable for cost-sensitive general composite structures. T700 is attractive when higher tensile strength is required. T800 is more relevant when both higher strength and higher modulus can provide a meaningful structural advantage.
The final choice should be based on performance requirements, processing method, laminate design, and cost.
JLON supplies carbon fiber fabric and carbon fiber reinforcement materials for industrial and structural composite applications.
Available products include woven carbon fiber fabric, unidirectional carbon fiber fabric, multiaxial carbon fiber fabric, spread tow carbon fiber fabric, and carbon fiber composite materials.
Different fiber grades, tow sizes, fabric weights, weave patterns, and widths can be selected according to customer specifications and application requirements.
JLON carbon fiber materials can be evaluated for applications including UAV and drone structures, marine composites, automotive components, sporting goods, industrial composite structures, lightweight sandwich panels, and other high-performance structural components.
JLON can also supply complementary composite materials such as PVC foam core, PET foam core, PMI foam core, fiberglass fabric, and vacuum bagging materials, helping composite manufacturers source different materials for the same project.
Instead of selecting carbon fiber only by a grade name, JLON can work with customers according to their required fiber grade, fabric construction, GSM, tow size, width, processing method, and end application.
When contacting JLON, buyers can provide an existing carbon fiber fabric specification or indicate the required fiber grade, tow size, GSM, weave, width, quantity, processing method, and application.
JLON can then evaluate suitable carbon fiber fabric options according to these requirements.
The key difference between T300, T700 and T800 carbon fiber is not simply that one grade is “better” than another.
T300 provides established standard-level performance and remains suitable for many industrial composite applications.
T700 offers considerably higher tensile strength while maintaining a similar modulus to T300, making it attractive for applications requiring improved strength without moving into a much higher modulus class.
T800 provides higher tensile strength and modulus and is more relevant to demanding lightweight structural applications where its additional performance can be effectively utilized.
For buyers of carbon fiber fabric, however, fiber grade should never be considered alone. Tow size, GSM, weave structure, fabric quality, resin system, manufacturing method, and laminate design all influence the performance of the finished composite.
When selecting T300, T700 or T800 carbon fiber fabric, the most effective approach is to start with the actual application requirements and then determine the appropriate combination of fiber grade and fabric construction.
JLON supplies carbon fiber fabric in different fiber grades, tow sizes, fabric weights, weave structures, and widths for composite applications. Contact JLON with your required carbon fiber grade, GSM, weave, width, quantity, and application to discuss a suitable carbon fiber fabric specification.
