2551 Corrosion Resistant Fluorosilicone
2551 is a 72 durometer, fuel- and solvent-resistant fluorosilicone elastomer filled with nickel-plated aluminum particles, available as fully cured electrically conductive sheet stock, continuous extrusion profiles, or as a ready-to-mold compound. It delivers shielding effectiveness of >112 dB (20 MHz–10 GHz) and >100 dB (10 GHz–40 GHz), both per MIL-DTL-83528, a volume resistivity of 0.03 ohm/cm (0.250 max), a compression set of 18% (70 hrs @ 100°C, 30 max), and galvanic corrosion of 0.10% per 168-hour salt spray (ASTM B117). Thermal stability range is -60°C to 220°C.
Key Properties
- Hardness Shore A (62–82 range): 69 (ASTM D2240)
- Tensile Strength (150 minimum): 200 psi (ASTM D412)
- Elongation % (50 min): 350% (ASTM D412)
- Compression Set % 70 hrs @ 100°C (30 max): 18 (ASTM D395)
- Volume Resistivity ohm/cm (0.250 max): 0.03 ohm/cm (ASTM D991)
- Thermal Stability Range: -60°C – 220°C
We want to help!
Enter your information and we'll get you in touch with our knowledgable staff. We know how important to the right product for your project.
Request a Consultation
- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Color | Dark Gray | — |
| Specific Gravity (1.80–2.30) | 2.15 | ASTM D792 |
Mechanical Properties
| Property | Value | Test Method |
| Shore A (62–82 range) | 69 | ASTM D2240 |
| Tensile psi (150 minimum) | 200 psi | ASTM D412 |
| Elongation % (50 min) | 350% | ASTM D412 |
| Tear “B” ppi (35 min) | 50 | ASTM D624 |
| Compression Set % 70 hrs @ 100°C (30 max) | 18 | ASTM D395 |
Thermal Properties
| Property | Value | Test Method |
| Thermal Stability Range | -60°C – 220°C | — |
Electrical Properties
| Property | Value | Test Method |
| Volume Resistivity ohm/cm (0.250 max) | 0.03 ohm/cm | ASTM D991 |
| Shielding Effectiveness 20 MHz–10 GHz | >112 dB | MIL-DTL-83528 |
| Shielding Effectiveness 10 GHz–40 GHz | >100 dB | MIL-DTL-83528 |
Environmental Performance
| Property | Value | Test Method |
| Galvanic Corrosion, 168 Hour Salt Spray | 0.10% | ASTM B117 |
| Shelf Life — Uncatalyzed | Indefinite (may need freshening after 1–2 years) | — |
| Shelf Life — Catalyzed | 6 months | — |
- EMI/RFI shielding gaskets for aluminum enclosures in fuel- or solvent-exposed environments requiring both corrosion resistance and fluorosilicone chemical compatibility
- Conductive elastomeric seals for aerospace and defense electronics exposed to fuels, hydraulic fluids, and solvents where nickel-plated aluminum filler minimizes galvanic corrosion
- Shielding gaskets requiring dual-band performance from 20 MHz through 40 GHz in a single elastomeric material
- Extruded conductive fluorosilicone profiles for continuous shielding in chemically aggressive and corrosion-prone environments
- Corrosion-resistant conductive seals for naval, aerospace, and ground vehicle electronics operating across -60°C to 220°C
Common industries: Defense, aerospace, naval, electronics, automotive, industrial equipment.
2551 is a corrosion-resistant fluorosilicone shielding elastomer filled with nickel-plated aluminum particles, providing both EMI shielding performance and resistance to galvanic corrosion, fuels, and solvents in a single material.
The fluorosilicone base adds fuel and solvent resistance beyond what standard silicone grades such as 2529 provide, making 2551 suitable for applications in chemically aggressive environments where both corrosion resistance and chemical compatibility are required. It is the only grade in this corrosion-resistant group to report dual-band shielding effectiveness, covering both 20 MHz–10 GHz (>112 dB) and 10 GHz–40 GHz (>100 dB) per MIL-DTL-83528.
Data was generated with the Varox catalyst system.
The material achieves 200 psi tensile strength, 350% elongation, and a Tear “B” of 50 ppi (ASTM D624). Compression Set is 18% (70 hrs @ 100°C, 30 max per ASTM D395), and galvanic corrosion is 0.10% after 168-hour salt spray per ASTM B117. 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 2551 from 2529 and 550-70?
2551 combines a fluorosilicone base (providing fuel and solvent resistance) with nickel-plated aluminum filler (providing galvanic corrosion resistance) — a combination not found in 2529 (standard silicone base) or 550-70 (silver-plated aluminum filler). It is the only grade in the group to report dual-band shielding effectiveness: >112 dB (20 MHz–10 GHz) and >100 dB (10 GHz–40 GHz). It also reports compression set of 18% (ASTM D395) — not listed on the 2529 TDS. Volume resistivity specification is 0.250 max, the most relaxed in the group.
Why is compression set critical for this material?
As a conductive fluorosilicone shielding gasket, 2551 must maintain intimate contact with mating surfaces — including in fuel and solvent environments — to sustain shielding effectiveness of >112 dB and volume resistivity of 0.03 ohm/cm. Compression Set of 18% at 70 hours at 100°C (ASTM D395, 30 max specification) confirms the gasket's ability to recover and maintain its cross-section under sustained clamping load, which is critical to long-term shielding performance.
What is the operating temperature range for 2551?
The thermal stability range for 2551 is -60°C to 220°C as listed on the TDS.
Is 2551 suitable for regulated or military environments?
No compliance standards or military specifications are listed on the manufacturer's TDS for this material. Shielding effectiveness data was measured per MIL-DTL-83528 method.
How should 2551 be specified?
Specify grade (2551), supply form (sheet stock, extrusion profile, or compound), thickness, compliance requirements, dimensional tolerances, and finished format.
