COOLTHERM 6410
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others

Main features
- 600 cP Mixed Viscosity
- Flexible Encapsulation Protection
- Room-Temperature Encapsulation Cure
Product Description
Circalok™ 6410 A/B Urethane Encapsulant is a two-component polyurethane casting elastomer formulated for tooling, mechanical goods, and model-making applications. The black mixed material has a typical viscosity of 600 cP at 25°C, supporting pouring and automatic meter/mix/dispense application. It uses a 17.5:10 resin-to-hardener ratio by weight and provides a typical 30-minute working life at 25°C. The system initially cures in 4 hours at 25°C or 1 hour at 65°C, with complete cure after one week at 25°C. The cured elastomer is flexible, with 55 Shore 00 hardness, 2.6 MPa tensile strength, and 700% elongation at break.
Key features
- Low mixed viscosity: 600 cP at 25°C supports pouring and meter/mix/dispense processing.
- Flexible cured elastomer: 55 Shore 00 hardness and 700% elongation at break.
- Room-temperature or mild heat cure: initial cure in 4 hours at 25°C or 1 hour at 65°C.
- Controlled two-part processing: 17.5:10 resin-to-hardener mix ratio by weight.
- Broad documented operating range: -50°C to +105°C.
Applications
- Tooling and mould-making applications
- Mechanical goods and flexible cast parts
- Model-making and prototype casting
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Mechanical Properties
Additional Information
Circalok™ 6410 A/B Urethane Encapsulant
A low-viscosity, two-component polyurethane system for room-temperature mixing, pouring, and curing in tooling, mechanical-goods, and model-making applications. The mixed material flows readily before curing to a soft, flexible black elastomer. A mild 65°C heat cycle can shorten the initial cure where the assembly and process permit.
Component and mixed-material properties
The resin is a black liquid and the hardener is an amber liquid. After mixing at the specified ratio, the system forms a black liquid with a lower viscosity than the resin component. Values are typical and are not specification limits.
| Property | 6410 A resin | 6410 B hardener | Mixed material |
|---|---|---|---|
| Appearance | Black liquid | Amber liquid | Black liquid |
| Viscosity at 25°C | 1,250 cP | 95 cP | 600 cP |
| Specific gravity | 1.02 | 1.00 | 1.04 |
| Working life at 25°C | 30 minutes after mixing | ||
Mix, de-air when needed, pour, and cure
Transfer the required amount of Circalok 6410 A resin to a clean container and add Circalok 6410 B hardener at 17.5 parts resin to 10 parts hardener by weight. Mix until uniform without whipping excessive air into the material. Where entrapped air is present, evacuate the mixture before pouring.
- Pour directly from the mixing container or use automatic meter/mix/dispense equipment.
- Initial cure is 4 hours at 25°C or 1 hour at 65°C.
- Complete cure is reached after one week at 25°C.
- Cure time begins after the material reaches the stated temperature; account for oven ramp and part thermal mass.
Storage and handling
Each component has a six-month shelf life when stored at 25°C in its original, unopened container. Before use, review the current product labels and applicable safety documentation. This material is for trained industrial or commercial personnel and is not intended for household or consumer application.
Flexible elastomer properties
The cured system is a soft, highly extensible polyurethane elastomer. These values are typical bulk-material properties and do not independently establish performance in a specific mould, encapsulated assembly, or loaded component.
| Property | Typical value | Interpretation boundary |
|---|---|---|
| Hardness | 55 Shore 00 | Bulk cured-material hardness; it does not define load response in every geometry. |
| Tensile strength at 25°C | 2.6 MPa (377 psi) | Bulk tensile property, not a universal assembly strength. |
| Elongation at break | 700% | Tensile specimen property; it does not by itself establish fatigue, tear, or long-term dimensional performance. |
| Documented operating temperature | -50°C to +105°C | Use within the documented range still requires validation of the actual part, load, environment, and duty cycle. |
Flexible casting for tooling, mechanical goods, and models
The published product scope is tooling, mechanical goods, and model making. Application-specific validation should address mould material, release strategy, section thickness, entrapped air, cure profile, mechanical loading, and operating environment.
Evaluate Circalok™ 6410 for your casting process
Krayden can help review batch size, mix-ratio control, de-airing, mould geometry, dispensing equipment, cure profile, demould timing, and mechanical-property requirements for Circalok™ 6410 A/B.





















