5052-H39 Aluminum Honeycomb Flex
Grade
also AMS-C-7438, MIL-C-7438
Flex = flex-Core
Non-hexagonal flexible cell shape that conforms to compound curvature without cell buckling or node fracture.
Values for the Flex condition
Other 5052-H39 Aluminum Honeycomb grades and fills
5052-H39 Aluminum Honeycomb is listed in 8 conditions; see the grade overview at 5052-H39 Aluminum Honeycomb.
Compare all 8 grades and fillsHide
| Grade · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness |
|---|---|---|---|---|---|
1.6 pcf | Lowest-density standard core for weight-critical, lightly loaded panels (radomes, interior partitions). | 0.45 | 1 | — | — |
2.3 pcf | Good stiffness-per-weight compromise for large-area architectural and transport sandwich panels. | 0.83 | 2 | — | — |
3.1-1/8-.0007Default 3.1 pcf | The industry-standard aerospace core density — best all-round strength, skin support and bond area. | 1 | 3 | — | — |
Cold rolled | Chromate-conversion or resin-coated foil for marine, floor-panel and high-humidity service where bare foil would pit. | 1 | 2 | 5 | — |
FlexThis page Flex-Core | Non-hexagonal flexible cell shape that conforms to compound curvature without cell buckling or node fracture. | 2 | 4 | — | — |
4.5 pcf | Higher-load floor panels, cargo liners and tooling plates where local crush resistance matters. | 2 | 5 | — | — |
5.7 pcf | Heavily loaded aircraft floor and helicopter deck panels needing high shear strength. | 3 | 7 | — | — |
8.1 pcf | Local reinforcement, energy-absorbing crush cores and hard-point regions of sandwich panels. | 6 | 11 | — | — |
What is 5052-H39 Aluminum Honeycomb Flex?
5052-H39 Aluminum Honeycomb Flex is 5052-H39 Aluminum Honeycomb in the Flex grade — non-hexagonal flexible cell shape that conforms to compound curvature without cell buckling or node fracture. 5052-H39 Aluminum Honeycomb Flex has a yield strength of 2 MPa (0.247 ksi) and a tensile strength of 4 MPa (0.522 ksi) — weaker than 89% of composite grades. The elastic modulus is 0.65 GPa (0.0943 Msi). 5052-H39 Aluminum Honeycomb Flex has a density of 0.07 g/cm³ (0.0025 lb/in³), lighter than 91% of composite grades. 3.1-1/8-.0007 is the default condition FabDigit quotes; Flex is available on request or by drawing note.
Advantages
- Lightweight — 0.07 g/cm³ (0.0025 lb/in³), better than 91% of composite grades
- Good UV / weathering resistance — 95/100, better than 78% of composite grades
Limitations
- Low strength — 2 MPa (0.247 ksi), worse than 89% of composite grades
- Low stiffness — 0.65 GPa (0.0943 Msi), worse than 86% of composite grades
5052-H39 Aluminum Honeycomb Flex properties
Typical room-temperature values for 5052-H39 Aluminum Honeycomb Flex; 12 are specific to this condition. Other listed values are 5052-H39 Aluminum Honeycomb reference data and may not represent this condition. Bars are the position among composite grades.
Physical1
5052-H39 Aluminum Honeycomb Flex has a density of 0.07 g/cm³ (0.0025 lb/in³), lighter than 91% of composite grades.
Mechanical8
5052-H39 Aluminum Honeycomb Flex has a yield strength of 2 MPa (0.247 ksi) and a tensile strength of 4 MPa (0.522 ksi) — weaker than 89% of composite grades. The elastic modulus is 0.65 GPa (0.0943 Msi).
Thermal7
5052-H39 Aluminum Honeycomb Flex is rated for continuous service to 177°C (351 °F). It conducts heat at 3.5 W/m·K (2.02 BTU/hr·ft·°F), better than 63% of composite grades. Thermal expansion is 23.8 µm/m·K (13.2 µin/in·°F).
Electrical1
5052-H39 Aluminum Honeycomb Flex has an electrical resistivity of 1.9×10⁻⁶ Ω·m.
Chemical & Environmental3
Corrosion resistance is good (67/100), worse than 69% of composite grades. UV resistance is excellent.
Sustainability4
Producing a kilogram of 5052-H39 Aluminum Honeycomb Flex takes about 215 MJ of energy and emits 14 kg of CO₂ — more than 50% of composite grades. Typical recycled content is 10%.
Manufacturability1
5052-H39 Aluminum Honeycomb Flex's machinability is fair (35/100, better than 50% of composite grades).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with 5052-H39 Aluminum Honeycomb Flex
Is 5052-H39 Aluminum Honeycomb easy to machine?
Cut with high-speed router, ultrasonic knife, waterjet or crush-free CNC blade; stabilize with potting compound, wax or ice-fill to prevent cell collapse and clean residue before bonding.
Can 5052-H39 Aluminum Honeycomb be welded?
Not weldable as a core — panels are assembled with film adhesive, foaming adhesive or brazing (special brazed-core grades only); node bonds define the temperature limit.
Can 5052-H39 Aluminum Honeycomb be formed, bent or molded?
Regular hex core forms only to gentle single curvature; use OX (overexpanded) or Flex-Core for tight single or compound curvature, or heat-form the cured panel.
What surface finishes work on 5052-H39 Aluminum Honeycomb?
Foil is supplied bare, chromate-converted or resin-coated; edges are usually closed with edge-fill, potting compound or metal channel, and exposed core should be sealed against moisture ingress.
5052-H39 Aluminum Honeycomb 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 |
|---|---|---|
| Mgprincipal solid-solution strengthener | 2.2 – 2.8 | 2.5 |
| Cr | 0.15 – 0.35 | 0.25 |
| Si | ≤ 0.25 | — |
| Fe | ≤ 0.4 | — |
| Cu | ≤ 0.1 | — |
| Mn | ≤ 0.1 | — |
| Zn | ≤ 0.1 | — |
| Others (each)total 0.15 max | ≤ 0.05 | — |
| Al | balance | — |
5052-H39 Aluminum Honeycomb Flex — frequently asked
What is 5052-H39 Aluminum Honeycomb Flex used for?
5052-H39 Aluminum Honeycomb Flex is typically used for aircraft floor and control-surface panels, radome cores, shipping containers, elevator and door panels and wind tunnel/test fixtures. In short: standard aerospace aluminum core; lower cost than 5056; wide cell and density range.
What is the yield strength of 5052-H39 Aluminum Honeycomb Flex?
5052-H39 Aluminum Honeycomb Flex has a typical yield strength of 2 MPa (0.247 ksi) and a tensile strength of 4 MPa (0.522 ksi) — weaker than 89% of composite grades. Strength varies by condition: see the 8 listed tempers.
Is 5052-H39 Aluminum Honeycomb Flex easy to machine?
Not especially — machinability is rated fair (35/100, better than 50% of composite grades). Cut with high-speed router, ultrasonic knife, waterjet or crush-free CNC blade; stabilize with potting compound, wax or ice-fill to prevent cell collapse and clean residue before bonding.
Can 5052-H39 Aluminum Honeycomb Flex be welded?
Not weldable as a core — panels are assembled with film adhesive, foaming adhesive or brazing (special brazed-core grades only); node bonds define the temperature limit.
What surface finishes work on 5052-H39 Aluminum Honeycomb Flex?
Foil is supplied bare, chromate-converted or resin-coated; edges are usually closed with edge-fill, potting compound or metal channel, and exposed core should be sealed against moisture ingress.
Can 5052-H39 Aluminum Honeycomb Flex be formed, bent or molded?
Regular hex core forms only to gentle single curvature; use OX (overexpanded) or Flex-Core for tight single or compound curvature, or heat-form the cured panel.
What is the maximum service temperature of 5052-H39 Aluminum Honeycomb Flex?
5052-H39 Aluminum Honeycomb Flex is rated for continuous use to about 177°C (351 °F), and briefly to 250°C. Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between 5052-H39 Aluminum Honeycomb 3.1-1/8-.0007 and 5052-H39 Aluminum Honeycomb Flex?
3.1-1/8-.0007 is the default condition — the industry-standard aerospace core density — best all-round strength, skin support and bond area. Flex: non-hexagonal flexible cell shape that conforms to compound curvature without cell buckling or node fracture. Yield strength is 1 MPa in 3.1-1/8-.0007 versus 2 MPa in Flex.
Sources
- AMS-C-7438 / MIL-C-7438 Core Material, Aluminum, for Sandwich Construction — SAE International / US DoD (2018)
- HexWeb Honeycomb Attributes and Properties (5052 aluminum core) — Hexcel (2019)
- PAMG-XR1 5052 Aluminum Honeycomb Data Sheet — Plascore (2020)
- ASTM C365 / C273 — Flatwise Compressive and Shear Properties of Sandwich Cores — ASTM International (2016)
- Aluminum Standards and Data (Teal Sheets), 5052 alloy — The Aluminum Association (2015)
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.