550-70 Corrosion Resistant Fluorosilicone
550-70 PASSIVATED is a corrosion-resistant, electrically conductive fluorosilicone elastomer filled with silver-plated aluminum, available as fully cured conductive sheet stock, continuous extrusion profiles, or as a ready-to-mold compound, and engineered to meet the shielding requirements specified in MIL-G-83528. It delivers shielding effectiveness of >125 dB (20 MHz–10 GHz, >90 dB specification) per MIL-DTL-83528, a volume resistivity of 0.005 ohm/cm (0.012 max per ASTM D991), a compression set of 29% (70 hours at 100°C, 30 max per ASTM D395 M-B), and a compression deflection of 6% (3.5% minimum per ASTM D575). Data was generated with the Varox catalyst system.
Key Properties
- Hardness Shore A (63–77 range): 70 (ASTM D2240)
- Tensile Strength (180 minimum): 330 psi (ASTM D412)
- Elongation % (Report): 245% (ASTM D412)
- Compression Set % (30 max.): 29% — 70 hours at 100°C (ASTM D395 M-B)
- Volume Resistivity ohm/cm (0.012 max.): .005 ohm/cm (ASTM D991)
- Thermal Stability Range: -60°C – 220°C
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Color | Tan/Dark Blue | — |
| Specific Gravity (1.75–2.25) | 2.10 | ASTM D792 |
Mechanical Properties
| Property | Value | Test Method |
| Shore A (63–77 range) | 70 | ASTM D2240 |
| Tensile psi (180 minimum) | 330 psi | ASTM D412 |
| Elongation % (Report) | 245% | ASTM D412 |
| Compression Set % (30 max.) | 29% (70 hours at 100°C) | ASTM D395 M-B |
| Compression Deflection (3.5% minimum) | 6% | ASTM D575 |
Thermal Properties
| Property | Value | Test Method |
| Thermal Stability Range | -60°C – 220°C | — |
Electrical Properties
| Property | Value | Test Method |
| Volume Resistivity ohm/cm (0.012 max.) | .005 ohm/cm | ASTM D991 |
| Shielding Effectiveness 20 MHz–10 GHz (>90 dB) | >125 | MIL-DTL-83528 |
Environmental Performance
| Property | Value | Test Method |
| Shelf Life — Uncatalyzed | Indefinite (may need freshening after 1–2 years) | — |
| Shelf Life — Catalyzed | 6 months | — |
Compliance
- MIL-G-83528 — Engineered to meet shielding requirements specified in MIL-G-83528 (as stated on TDS)
- EMI/RFI shielding gaskets for aluminum enclosures requiring maximum shielding effectiveness with corrosion-resistant passivated silver-plated aluminum filler
- Conductive fluorosilicone seals for defense and aerospace electronics exposed to fuels, solvents, and humid or salt-laden environments
- Shielding gaskets requiring >125 dB attenuation from 20 MHz to 10 GHz in enclosures where galvanic compatibility with aluminum housings is required
- Extruded conductive corrosion-resistant profiles for continuous shielding in high-humidity or marine environments
- Press-molded shielding components for applications demanding both MIL-G-83528 shielding performance and fuel/solvent resistance across -60°C to 220°C
Common industries: Defense, aerospace, naval, electronics, telecommunications, ground vehicle electronics.
550-70 PASSIVATED is a corrosion-resistant conductive fluorosilicone elastomer in which silver-plated aluminum particles are passivated to reduce galvanic activity, combining the high shielding performance of silver-containing filler with corrosion resistance for use with aluminum housings and enclosures. The product is identified on the TDS as SSP-550-70 PASSIVATED and is engineered to meet the shielding requirements specified in MIL-G-83528.
It delivers the highest shielding effectiveness in this corrosion-resistant product group at >125 dB (20 MHz–10 GHz, against a >90 dB MIL-DTL-83528 specification). It is supplied as fully cured sheet stock, continuous extrusion profiles, or ready-to-mold compound, with data generated using the Varox catalyst system.
The material achieves 330 psi tensile strength — the highest in this corrosion-resistant group — 245% elongation, and a specific gravity of 2.10. Compression Set is 29% (70 hours at 100°C, 30 max per ASTM D395 M-B) and Compression Deflection is 6% (3.5% minimum per ASTM D575). Volume resistivity of 0.005 ohm/cm is the lowest in the group, within the 0.012 max specification. Uncatalyzed shelf life is indefinite (may need freshening after 1–2 years); catalyzed shelf life is 6 months. Cold storage will extend shelf life.
What differentiates 550-70 from 2529 and 2551?
550-70 PASSIVATED uses silver-plated aluminum filler that has been passivated for corrosion resistance — providing higher shielding effectiveness (>125 dB) than the nickel-plated aluminum grades 2529 (>110 dB) and 2551 (>112 dB) — in a fluorosilicone base. It has the lowest volume resistivity in the group (0.005 ohm/cm, 0.012 max) and the highest tensile strength (330 psi). It is the only grade in the group to report compression deflection (ASTM D575) and to reference MIL-G-83528 in the product description. Colors are Tan/Dark Blue versus Dark Gray for 2529 and 2551.
Why is compression set critical for this material?
As a conductive elastomeric shielding gasket, 550-70 must maintain intimate contact with mating metal surfaces to sustain shielding effectiveness of >125 dB and volume resistivity of 0.005 ohm/cm throughout its service life. Compression Set of 29% at 70 hours at 100°C (ASTM D395 M-B, 30 max specification) confirms the gasket recovers close to its original cross-section under sustained clamping load, preserving the conductive interface. The compression deflection of 6% (ASTM D575, 3.5% minimum specification) characterizes the material's behavior under compressive load.
What is the operating temperature range for 550-70?
The thermal stability range for 550-70 is -60°C to 220°C as listed on the TDS.
Is 550-70 suitable for regulated or military environments?
The TDS states that SSP-550-70 PASSIVATED is engineered to meet the shielding requirements specified in MIL-G-83528. Shielding effectiveness is measured per MIL-DTL-83528. No QPL listing or additional compliance certifications are stated on the manufacturer's TDS for this material.
How should 550-70 be specified?
Specify grade (550-70 PASSIVATED), supply form (sheet stock, extrusion profile, or compound), thickness, color (Tan or Dark Blue), compliance requirements, dimensional tolerances, and finished format.
