LOCTITE 641
Harmonization Code : 3907.30.00.40 | Epoxy Mold Compounds containing by weight more than 70 % silicon dioxide
Main features
- Serviceable Medium-Strength Retention
- Controlled Medium-Viscosity Flow
- Anaerobic One-Part Metal Cure
Product Description
LOCTITE 641 is a yellow, medium-viscosity one-component anaerobic retaining compound for cylindrical metal parts that may require later service disassembly. It cures between close-fitting metal surfaces after air is excluded and is commonly used to retain bearings on shafts or in housings. The shear-thinning viscosity profile supports controlled coverage during assembly. After 24 hours at 22 deg C, the cured compound develops at least 6.5 N/mm^2 compressive-shear strength on steel pins and collars. Medium-strength retention balances secure positioning with removal using appropriate service methods.
Key features
- Serviceable medium-strength retention: The cured joint retains cylindrical parts while supporting later disassembly with appropriate methods.
- Controlled medium-viscosity flow: Brookfield viscosity data support coverage without excessive run-off during assembly.
- Anaerobic one-part processing: The compound cures in confined metal fits without mixing.
Applications / Suitable for
- Retaining bearings on shafts
- Retaining bearings in housings
- Bonding cylindrical metal parts requiring service disassembly
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Thermal Properties
Physical Properties
Additional Information
As-supplied / before-processing properties
Typical values and characteristics for the product before cure, application, or assembly.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Yellow liquid | - | As supplied |
| Chemical type | Methacrylate ester | - | One-component material |
| Specific gravity | 1.07 | - | 25 deg C |
| Viscosity | 1,215 to 2,750 | mPa s | Brookfield RVT, spindle 2, 2.5 rpm, 25 deg C |
| Viscosity | 400 to 800 | mPa s | Brookfield RVT, spindle 2, 20 rpm, 25 deg C |
| Viscosity | 90 to 180 | mPa s | EN 12092-MV, 277 s^-1, 25 deg C |
| Cure mechanism | Anaerobic | - | Confined between close-fitting metal surfaces |
After-processing / final-state properties
Typical values for the cured, bonded, treated, or in-service product under the listed conditions.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Compressive shear strength | >=6.5 | N/mm^2 | Steel pins and collars, cured 24 h at 22 deg C |
| Coefficient of thermal expansion | 80 x 10^-6 | K^-1 | Cured material |
| Thermal conductivity | 0.1 | W/(m K) | Cured material |
| Specific heat | 0.3 | kJ/(kg K) | Cured material |
