8552
8552 is Hexcel's 180 °C-cure toughened epoxy prepreg matrix, available with IM7, IM10 and AS4 carbon fiber as unidirectional tape, plain weave and 5-harness satin, plus the 8552S, S2 glass and neat resin variants.
Reference datasheet — 8552 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 IM7-8552-UD condition
8552 grades and fills
8552 is supplied in 8 conditions, soft to hard. IM7-8552-UD is the default FabDigit quotes; the values on this page are for it.
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 | 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?
8552 is Hexcel's 180 °C-cure toughened epoxy prepreg matrix, available with IM7, IM10 and AS4 carbon fiber as unidirectional tape, plain weave and 5-harness satin, plus the 8552S, S2 glass and neat resin variants. It is a de-facto standard for modern aerospace and high-performance composite structure, with UD laminate at 2720 MPa tensile strength, 164 GPa modulus, 1.6 % elongation and 1.57 g/cm³. Limits are roughly 120 °C service temperature, −18 °C storage with tracked out-life, autoclave processing and poor machinability (score 30); 5250-4 BMI covers higher service temperatures. 8552 has a density of 1.57 g/cm³ (0.0567 lb/in³), lighter than 55% of composite grades. Its glass-transition temperature is 200°C (392 °F). 8552 has a tensile strength of 2,720 MPa (395 ksi), stronger than 78% of composite grades. Elongation at break is 1.6% and the elastic modulus is 164 GPa (23.8 Msi).
What is 8552 used for?
- commercial aircraft structures
- space launch vehicles
- high-performance automotive/racing parts
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 properties
Typical room-temperature values for 8552-IM7-8552-UD; bars are the position among composite grades.
Physical4
8552 has a density of 1.57 g/cm³ (0.0567 lb/in³), lighter than 55% of composite grades. Its glass-transition temperature is 200°C (392 °F).
Mechanical10
8552 has a tensile strength of 2,720 MPa (395 ksi), stronger than 78% of composite grades. Elongation at break is 1.6% and the elastic modulus is 164 GPa (23.8 Msi).
Thermal6
8552 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 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 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's machinability is poor (30/100, worse than 54% 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. 8552 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with 8552
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.
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 |
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.
How much does 8552 cost?
8552 is a high-cost composite ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
8552 — frequently asked
What is 8552 used for?
8552 is typically used for commercial aircraft structures, space launch vehicles and high-performance automotive/racing parts. In short: de-facto aerospace epoxy standard; toughened, damage tolerant; autoclave-cure prepreg system.
What is the tensile strength of 8552?
8552 has a typical tensile strength of 2,720 MPa (395 ksi) — stronger than 78% of composite grades. Strength varies by condition: see the 8 listed tempers.
Is 8552 easy to machine?
Not especially — machinability is rated poor (30/100, worse than 54% of composite grades). Trim and drill cured laminates with PCD or diamond-coated tools, high speed / low feed, backing plates and vacuum extraction to avoid delamination and respirable dust.
Can 8552 be welded?
Not weldable — join by adhesive bonding (film adhesive, e.g. epoxy paste/FM-type) or mechanical fasteners with sealed, galvanically compatible (Ti/CRES) hardware.
What surface finishes work on 8552?
Sand/peel-ply prepared surface, epoxy primer plus polyurethane topcoat for UV protection; add surfacing film or copper mesh where lightning-strike protection is required.
Can 8552 be formed, bent or molded?
Hand or ATL/AFP lay-up of frozen prepreg, debulk, then autoclave cure typically 180 °C for 2 h at 7 bar with 2–3 °C/min ramps; -18 °C storage and limited out-life must be tracked.
What is the maximum service temperature of 8552?
8552 is rated for continuous use to about 120°C (248 °F), and briefly to 180°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does 8552 cost?
8552 is a high-cost composite ($$$$), 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
- 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; 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.