kSil® GP50
kSil® GP50 is a general purpose solid silicone elastomer rated at 50 Shore A, offering a medium hardness profile with good elongation and low compression set for a broad range of sealing, gasketing, and food-contact applications. It delivers 9 MPa (~1305 psi) tensile strength and 450% elongation, with compression set of 16% (22 hours @ 300°F) and 15% (24 hours @ 150°C). The material meets multiple international compliance standards including FDA 21 CFR 177.2600, FAR 25.853, FMVSS 302, and WRAS.
Key Properties
- Durometer: 50 Shore A — ISO 48-4
- Tensile Strength: 9 MPa (~1305 psi) — ISO 37 Type 2
- Elongation: 450 % — ISO 37 Type 2
- Compression Set, 22 Hours @ 300°F: 16 % — ISO 815, 22h @175°C
- Thermal Conductivity: 0.24 W/m·°C — ASTM C518
Tear Strength: 20 N/mm (~114 ppi) — ASTM D624 Die B
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- Specifications
- Applications
- General Info
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Physical Properties
| Property | Value | Unit | Test Method |
| Colors Available | Translucent, Red Iron Oxide (RIO), Black, White, Blue | Visual | Visual |
Mechanical Properties
| Property | Value | Unit | Test Method |
| Durometer | 50 | Shore A | ISO 48-4 |
| Tensile Strength | 9 MPa (~1305 psi) | MPa | ISO 37 Type 2 |
| Elongation | 450 | % | ISO 37 Type 2 |
| Compression Set — 22 Hours @ 300°F | 16 | % | ISO 815, 22h @175°C |
| Compression Set — 24 Hours @ 150°C | 15 | % | ISO 815, 24h @150°C |
| Tear Strength | 20 N/mm (~114 ppi) | N/mm | ASTM D624 Die B |
Thermal Properties
| Property | Value | Unit | Test Method |
| Thermal Conductivity | 0.24 | W/m·°C | ASTM C518 |
Regulatory / Compliance Data
| Property | Value | Test Method |
| FDA 21 CFR 177.2600 | Compliant | — |
| FAR 25.853 | Compliant | — |
| FMVSS 302 | Compliant | — |
| WRAS | Compliant | — |
Compliance
- FDA 21 CFR 177.2600 — Compliant
- FAR 25.853 — Compliant
- FMVSS 302 — Compliant
- WRAS — Compliant
- Gaskets and seals requiring a medium-hardness silicone with low compression set and broad compliance
- Food contact components requiring FDA 21 CFR 177.2600 compliant silicone
- Aerospace sealing assemblies compliant with FAR 25.853
- Automotive sealing components compliant with FMVSS 302
- Water contact applications requiring WRAS-compliant silicone elastomer
Common industries: Food processing, aerospace, automotive, water infrastructure, general industrial.
kSil® GP50 is a medium-hardness grade in the kSil® GP general purpose solid silicone series at 50 Shore A, positioned between the more flexible GP30/GP40 grades and the firmer GP60/GP70 grades. It offers a low compression set of 15–16% across two test conditions — lower than any softer grade in the series — making it well suited for sealing applications where long-term elastic recovery is a priority.
At 9 MPa (~1305 psi) tensile strength and 450% elongation, it delivers a practical balance of mechanical strength and compliance for a broad range of gaskets, seals, and food contact components across aerospace, automotive, food processing, and water contact environments.
Colors are available as Translucent, Red Iron Oxide (RIO), Black, White, and Blue. Shelf life is defined as the duration of time for which the product will meet the physical characteristics outlined on the TDS; it does not guarantee the product’s usefulness in all applications.
Compliant with FDA 21 CFR 177.2600, FAR 25.853, FMVSS 302, and WRAS.
What differentiates kSil® GP50 from softer and firmer grades in the GP series?
kSil® GP50 achieves the lowest compression set among the softer GP grades at 15–16% across both test conditions — lower than GP30 (20%/23%) and GP40 (22%/25%) — while maintaining a medium 50 Shore A durometer and 450% elongation. It is the appropriate selection when long-term elastic recovery under compression is a priority alongside moderate compliance, offering better sealing force retention than the softer grades without the firmness of GP60 or GP70.
Why is compression set an important consideration for solid silicone elastomers?
Compression set measures how well an elastomer recovers its original thickness after sustained compression. In sealing applications, a material with high compression set will permanently deform over time, reducing sealing force and allowing leak paths to develop. kSil® GP50 achieves 16% compression set (22 hours @ 300°F per ISO 815) and 15% (24 hours @ 150°C) — among the lowest in the series for grades with two test conditions — supporting sustained sealing performance across its service temperature range.
What is the operating temperature range for kSil® GP50?
No operating temperature range is specified on the manufacturer's TDS for this material. Compression set conditions tested at 300°F (175°C) and 150°C indicate suitability for elevated temperature service. Contact H-O Products Corporation for application-specific temperature guidance.
Is kSil® GP50 suitable for aerospace, automotive, food contact, and regulated environments?
Yes. kSil® GP50 meets FDA 21 CFR 177.2600, FAR 25.853 (aerospace), FMVSS 302 (automotive), and WRAS (water contact), as stated on the TDS.
How should kSil® GP50 be specified?
Specify grade (kSil® GP50), thickness, color (Translucent, Red Iron Oxide, Black, White, or Blue), compliance requirements, dimensional tolerances, and finished format.
