3501-6 QI-AS4
Reinforced grade
QI-AS4 = 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.
Values for the QI-AS4 condition
Other 3501-6 grades and fills
3501-6 is listed in 6 conditions; see the grade overview at 3501-6.
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 |
QI-AS4This page 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 QI-AS4?
3501-6 QI-AS4 is 3501-6 in the QI-AS4 grade — design-level numbers for a balanced/symmetric skin layup — use for panel sizing rather than lamina allowables. 3501-6 QI-AS4 has a tensile strength of 620 MPa (89.9 ksi), stronger than 69% of composite grades. Elongation at break is 1.2% and the elastic modulus is 52 GPa (7.54 Msi). 3501-6 QI-AS4 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). UD-AS4 is the default condition FabDigit quotes; QI-AS4 is available on request or by drawing note.
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 QI-AS4 properties
Typical room-temperature values for 3501-6 QI-AS4; 17 are specific to this condition. Other listed values are 3501-6 reference data and may not represent this condition. Bars are the position among composite grades.
Physical4
3501-6 QI-AS4 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 QI-AS4 has a tensile strength of 620 MPa (89.9 ksi), stronger than 69% of composite grades. Elongation at break is 1.2% and the elastic modulus is 52 GPa (7.54 Msi).
Thermal7
3501-6 QI-AS4 is rated for continuous service to 121°C (250 °F). It conducts heat at 2.5 W/m·K (1.44 BTU/hr·ft·°F), better than 61% of composite grades. Thermal expansion is 2.2 µm/m·K (1.22 µin/in·°F).
Electrical1
3501-6 QI-AS4 has an electrical resistivity of 3×10⁻⁵ 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 QI-AS4 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 QI-AS4's machinability is fair (36/100, better than 53% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 3501-6 QI-AS4
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.
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.
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 |
3501-6 QI-AS4 — frequently asked
What is 3501-6 QI-AS4 used for?
3501-6 QI-AS4 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 QI-AS4?
3501-6 QI-AS4 has a typical tensile strength of 620 MPa (89.9 ksi) — stronger than 69% of composite grades. Strength varies by condition: see the 6 listed tempers.
Is 3501-6 QI-AS4 easy to machine?
Not especially — machinability is rated fair (36/100, better than 53% 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 QI-AS4 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 QI-AS4?
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 QI-AS4 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 QI-AS4?
3501-6 QI-AS4 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.
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. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.