8552 AS4-8552-UD
Reinforced grade
AS4-8552-UD = aS4/8552
Lower-cost standard-modulus version for secondary structure, ribs and tooling where IM7 stiffness is not required.
Values for the AS4-8552-UD condition
Other 8552 grades and fills
8552 is listed in 8 conditions; see the grade overview at 8552.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
8552 neat resin | Reference matrix properties for analysis, resin films and adhesive/filler applications; not a structural product on its own. | — | 100 | 1.7 | — |
Modified 8552 resin version for woven-fabric prepregs | Flow/tack-modified version of the 8552 chemistry qualified mainly on woven carbon fabric (NCAMP 8552S/AS4 PW). | — | 880 | 1.4 | 87 Shore D |
AS4/8552 plain-weave fabric prepreg | Fabric form for drapable skins, complex curvature, repairs and damage-tolerant surface plies. | — | 900 | 1.3 | — |
IM7/8552 satin-weave fabric prepreg | Intermediate-modulus fabric for stiff, drapable skins and hybrid UD/fabric stacks. | — | 1,000 | 1.3 | 88 Shore D |
S2-glass/8552 | Use where electrical insulation, radar transparency, high strain-to-failure or impact/ballistic energy absorption is required. | — | 1,750 | 3 | — |
AS4-8552-UDThis page AS4/8552 | Lower-cost standard-modulus version for secondary structure, ribs and tooling where IM7 stiffness is not required. | — | 2,210 | 1.5 | — |
IM7-8552-UDDefault IM7/8552 | Default aerospace primary-structure choice: highest strength/stiffness combination with the largest published allowables database. | — | 2,720 | 1.6 | — |
IM10/8552 | Choose when maximum tensile strength/stiffness per unit weight is needed (highly loaded spars, launch structures). | — | 3,300 | 1.8 | 89 Shore D |
What is 8552 AS4-8552-UD?
8552 AS4-8552-UD is 8552 in the AS4-8552-UD grade — lower-cost standard-modulus version for secondary structure, ribs and tooling where IM7 stiffness is not required. 8552 AS4-8552-UD has a tensile strength of 2,210 MPa (321 ksi), stronger than 78% of composite grades. Elongation at break is 1.5% and the elastic modulus is 141 GPa (20.5 Msi). 8552 AS4-8552-UD 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). IM7-8552-UD is the default condition FabDigit quotes; AS4-8552-UD is available on request or by drawing note.
Advantages
- Low moisture uptake — 0.05%, better than 94% of composite grades
- Good corrosion resistance — 90/100, better than 85% of composite grades
Limitations
- High embodied carbon — 30 kg CO₂/kg, worse than 80% of composite grades
- Limited service temperature — 120°C (248 °F), worse than 78% of composite grades
8552 AS4-8552-UD properties
Typical room-temperature values for 8552 AS4-8552-UD; 10 are specific to this condition. Other listed values are 8552 reference data and may not represent this condition. Bars are the position among composite grades.
Physical4
8552 AS4-8552-UD 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
8552 AS4-8552-UD has a tensile strength of 2,210 MPa (321 ksi), stronger than 78% of composite grades. Elongation at break is 1.5% and the elastic modulus is 141 GPa (20.5 Msi).
Thermal6
8552 AS4-8552-UD is rated for continuous service to 120°C (248 °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
8552 AS4-8552-UD has an electrical resistivity of 1.5×10⁻⁵ Ω·m.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), better than 85% of composite grades. UV resistance is poor.
Sustainability4
Producing a kilogram of 8552 AS4-8552-UD takes about 500 MJ of energy and emits 30 kg of CO₂ — more than 84% of composite grades. Typical recycled content is 0%.
Manufacturability3
8552 AS4-8552-UD's machinability is poor (30/100, worse than 54% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 8552 AS4-8552-UD
Is 8552 easy to machine?
Trim and drill cured laminates with PCD or diamond-coated tools, high speed / low feed, backing plates and vacuum extraction to avoid delamination and respirable dust.
Can 8552 be welded?
Not weldable — join by adhesive bonding (film adhesive, e.g. epoxy paste/FM-type) or mechanical fasteners with sealed, galvanically compatible (Ti/CRES) hardware.
Can 8552 be formed, bent or molded?
Hand or ATL/AFP lay-up of frozen prepreg, debulk, then autoclave cure typically 180 °C for 2 h at 7 bar with 2–3 °C/min ramps; -18 °C storage and limited out-life must be tracked.
What surface finishes work on 8552?
Sand/peel-ply prepared surface, epoxy primer plus polyurethane topcoat for UV protection; add surfacing film or copper mesh where lightning-strike protection is required.
8552 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 (IM7 / AS4 reinforcement)wt % in cured UD laminate; ≈57–60 vol % | 62 – 70 | 66 |
| epoxy resin (tetrafunctional TGDDM + difmatrix backbone | ≈ 24 | 24 |
| DDS aromatic amine curing agent4,4'-diaminodiphenyl sulfone type hardener | ≈ 6 | 6 |
| thermoplastic toughener (polyethersulfonprovides damage tolerance / CAI | ≈ 4 | 4 |
8552 AS4-8552-UD — frequently asked
What is 8552 AS4-8552-UD used for?
8552 AS4-8552-UD is typically used for commercial aircraft structures, space launch vehicles and high-performance automotive/racing parts. In short: de-facto aerospace epoxy standard; toughened, damage tolerant; autoclave-cure prepreg system.
What is the tensile strength of 8552 AS4-8552-UD?
8552 AS4-8552-UD has a typical tensile strength of 2,210 MPa (321 ksi) — stronger than 78% of composite grades. Strength varies by condition: see the 8 listed tempers.
Is 8552 AS4-8552-UD easy to machine?
Not especially — machinability is rated poor (30/100, worse than 54% of composite grades). Trim and drill cured laminates with PCD or diamond-coated tools, high speed / low feed, backing plates and vacuum extraction to avoid delamination and respirable dust.
Can 8552 AS4-8552-UD be welded?
Not weldable — join by adhesive bonding (film adhesive, e.g. epoxy paste/FM-type) or mechanical fasteners with sealed, galvanically compatible (Ti/CRES) hardware.
What surface finishes work on 8552 AS4-8552-UD?
Sand/peel-ply prepared surface, epoxy primer plus polyurethane topcoat for UV protection; add surfacing film or copper mesh where lightning-strike protection is required.
Can 8552 AS4-8552-UD be formed, bent or molded?
Hand or ATL/AFP lay-up of frozen prepreg, debulk, then autoclave cure typically 180 °C for 2 h at 7 bar with 2–3 °C/min ramps; -18 °C storage and limited out-life must be tracked.
What is the maximum service temperature of 8552 AS4-8552-UD?
8552 AS4-8552-UD is rated for continuous use to about 120°C (248 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- HexPly 8552 Epoxy Matrix Product Data Sheet — Hexcel Corporation (2020)
- NCAMP Material Property Data Report — Hexcel 8552 IM7 Unidirectional Prepreg (CAM-RP-2009-015) — NIAR/NCAMP, Wichita State University (2011)
- NCAMP Qualification Reports — Hexcel 8552 AS4 and 8552S woven fabric prepregs — NIAR/NCAMP (2016)
- CMH-17 Composite Materials Handbook, Vol. 2 — Polymer Matrix Composites Material Properties — SAE International (2012)
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.