3501-6
3501-6 is a 177 °C (350 °F)-cure epoxy prepreg matrix from Hexcel, supplied with AS4, T300 and IM6 carbon fiber as unidirectional tape, 8-harness satin fabric, quasi-isotropic layups and neat resin.
Reference datasheet — 3501-6 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the UD-AS4 condition
3501-6 grades and fills
3501-6 is supplied in 6 conditions, soft to hard. UD-AS4 is the default FabDigit quotes; the values on this page are for it.
Compare all 6 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
3501-6 neat cured resin casting | Unreinforced cured matrix data — used for micromechanics modelling, adhesive/film comparison and toughness benchmarking. | 68 | 1.7 | 108 HRM | |
AS4/3501-6 quasi-isotropic laminate [0/±45/90]s | Design-level numbers for a balanced/symmetric skin layup — use for panel sizing rather than lamina allowables. | 620 | 1.2 | ||
AS4 8-harness satin fabric / 3501-6 | Woven-fabric prepreg for drapeable contoured skins and better handling/damage tolerance at the cost of ~25% lower in-plane properties. | 780 | 1.2 | ||
T300/3501-6 unidirectional tape | Standard-modulus Toray T300 version — the most common benchmark system in composite-mechanics literature and FE material libraries. | 1,700 | 1.3 | ||
UD-AS4Default AS4/3501-6 unidirectional tape | The industry-reference 350 °F-cure UD tape — pick for maximum axial stiffness/strength in laminated aerospace structure. | 2,100 | 1.5 | ||
IM6/3501-6 intermediate-modulus unidirectional tape | Choose when stiffness- and tension-critical (IM6/IM7 fibre) performance is needed; matrix-limited compression and toughness are unchanged. | 2,700 | 1.5 |
What is 3501-6?
3501-6 is a 177 °C (350 °F)-cure epoxy prepreg matrix from Hexcel, supplied with AS4, T300 and IM6 carbon fiber as unidirectional tape, 8-harness satin fabric, quasi-isotropic layups and neat resin. Engineers specify it as the industry reference aerospace prepreg system with a long-established property database: UD AS4 laminate gives 2100 MPa tensile strength, 142 GPa modulus and 1.45 % elongation at 1.58 g/cm³. Service is limited to about 121 °C, the untoughened resin has lower damage tolerance than current systems, and frozen storage plus autoclave cure are required; 8552 is the usual toughened replacement. 3501-6 has a density of 1.58 g/cm³ (0.0571 lb/in³), lighter than 54% of composite grades. Its glass-transition temperature is 200°C (392 °F). 3501-6 has a tensile strength of 2,100 MPa (305 ksi), stronger than 77% of composite grades. Elongation at break is 1.5% and the elastic modulus is 142 GPa (20.6 Msi).
What is 3501-6 used for?
- aircraft primary/secondary structures
- unmanned aerial vehicles
- structural test coupons
Advantages
- Low moisture uptake — 0.1%, better than 85% of composite grades
Limitations
- Degrades in UV without stabilisers — 25/100, worse than 86% of composite grades
3501-6 properties
Typical room-temperature values for 3501-6-UD-AS4; bars are the position among composite grades.
Physical4
3501-6 has a density of 1.58 g/cm³ (0.0571 lb/in³), lighter than 54% of composite grades. Its glass-transition temperature is 200°C (392 °F).
Mechanical10
3501-6 has a tensile strength of 2,100 MPa (305 ksi), stronger than 77% of composite grades. Elongation at break is 1.5% and the elastic modulus is 142 GPa (20.6 Msi).
Thermal7
3501-6 is rated for continuous service to 121°C (250 °F). It conducts heat at 4 W/m·K (2.31 BTU/hr·ft·°F), better than 63% of composite grades. Thermal expansion is -0.4 µm/m·K (-0.222 µin/in·°F).
Electrical1
3501-6 has an electrical resistivity of 1.6×10⁻⁵ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), better than 77% of composite grades. UV resistance is poor.
Sustainability4
Producing a kilogram of 3501-6 takes about 300 MJ of energy and emits 24 kg of CO₂ — more than 68% of composite grades. Typical recycled content is 0%.
Manufacturability3
3501-6's machinability is fair (35/100, better than 50% of composite grades).
Common Calculations4
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the composite family
Yield strength against density for every composite grade FabDigit runs. 3501-6 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 3501-6
Is 3501-6 easy to machine?
Trim and drill with PCD or diamond-coated tooling at high speed/low feed, backing plate and dust extraction required — the cured laminate is highly abrasive and delaminates on breakout.
Can 3501-6 be welded?
Not weldable; join by co-cure, secondary bonding with 350 °F film adhesive (e.g. FM300), or bolted joints with oversize washers and sealant.
Can 3501-6 be formed, bent or molded?
Hand or ATL layup of frozen prepreg, debulk every few plies, autoclave cure 2 h at 177 °C under 0.59 MPa with 1.5–3 °C/min ramp; keep out-time under ~10 days at 21 °C.
3501-6 chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| carbon fiber (AS4 PAN-based)cured laminate weight fraction; ≈60–63 vol%, prepreg resin content ≈34–35 wt% | 62 – 70 | 66 |
| TGMDA epoxy (tetraglycidyl-4,4'-methylen≈56 parts of the 3501-6 resin formulation | ≈ 19 | 19 |
| epoxy novolac (EPN-type)≈25 parts of resin | ≈ 8 | 8 |
| DDS (4,4'-diaminodiphenyl sulfone) curin≈18–20 parts of resin | ≈ 6.5 | 6.5 |
| BF3·monoethylamine catalystaccelerator, <1 part | ≈ 0.2 | 0.2 |
What surface finishes work on 3501-6?
Peel-ply or light sand to remove the resin-rich surface, then prime and paint / apply surfacing film for UV and moisture protection; isolate from aluminium with glass ply or sealant to prevent galvanic corrosion.
How much does 3501-6 cost?
3501-6 is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
3501-6 — frequently asked
What is 3501-6 used for?
3501-6 is typically used for aircraft primary/secondary structures, unmanned aerial vehicles and structural test coupons. In short: industry reference aerospace prepreg; classic 177 °C-cure epoxy; untoughened, extensively characterised.
What is the tensile strength of 3501-6?
3501-6 has a typical tensile strength of 2,100 MPa (305 ksi) — stronger than 77% of composite grades. Strength varies by condition: see the 6 listed tempers.
Is 3501-6 easy to machine?
Not especially — machinability is rated fair (35/100, better than 50% of composite grades). Trim and drill with PCD or diamond-coated tooling at high speed/low feed, backing plate and dust extraction required — the cured laminate is highly abrasive and delaminates on breakout.
Can 3501-6 be welded?
Not weldable; join by co-cure, secondary bonding with 350 °F film adhesive (e.g. FM300), or bolted joints with oversize washers and sealant.
What surface finishes work on 3501-6?
Peel-ply or light sand to remove the resin-rich surface, then prime and paint / apply surfacing film for UV and moisture protection; isolate from aluminium with glass ply or sealant to prevent galvanic corrosion.
Can 3501-6 be formed, bent or molded?
Hand or ATL layup of frozen prepreg, debulk every few plies, autoclave cure 2 h at 177 °C under 0.59 MPa with 1.5–3 °C/min ramp; keep out-time under ~10 days at 21 °C.
What is the maximum service temperature of 3501-6?
3501-6 is rated for continuous use to about 121°C (250 °F), and briefly to 177°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 3501-6 cost?
3501-6 is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- 3501-6 epoxy matrix prepreg data — Hercules / Hexcel (1990)
- MIL-HDBK-17 (CMH-17) Vol. 2 — Polymer Matrix Composites, AS4/3501-6 data set — US DoD / CMH-17 (2002)
- ASM Engineered Materials Handbook Vol. 1 — Composites — ASM International (1987)
- ASTM D3039 / D6641 / D2344 / D790 test methods for composite laminates — ASTM (2017)
- Composite lamina property compilations (Tsai/Daniel-Ishai reference data) — academic literature (2006)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.