LOCTITE 661

Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.

LOCTITE 661

Main features

  • Dual Anaerobic and UV Cure
  • Low-Viscosity Shaft Component Retention
  • High-Strength Steel Component Retention

Product Description

LOCTITE 661 is a one-component, low-viscosity urethane methacrylate retaining compound with anaerobic and UV cure. It bonds close-fitting cylindrical metal parts and can cure either when confined without air between mating surfaces or when exposed to UV light of sufficient intensity. Typical applications include gears and sprockets on gearbox shafts and rotors on electric motor shafts. After 24 hours at 23 deg C, compressive shear strength on steel pins and collars is 15 N/mm^2 per ISO 10123. Glass microscope slides reach fixture strength in 14 seconds under UV light at 6 mW/cm^2 measured at 365 nm.

Key features

  • Dual cure mechanism: Combines anaerobic cure in confined metal interfaces with UV-light cure.
  • Fast UV fixture: Glass microscope slides reach fixture strength in 14 seconds at 6 mW/cm^2 measured at 365 nm.
  • Shaft component retention: Typical uses include gears, sprockets and motor-shaft rotors.

Applications

Retaining gears and sprockets on gearbox shafts and rotors on motor shafts.

Product Family

LOCTITE 661

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TDS, SDS & Technical Documents

Technical Specifications

General Properties
Appearance
Appearance at room temperature.
Yellow to dark amber translucent to opaque liquid
Chemistry Type
Urethane methacrylate
Specific Gravity
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume. For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
1.1
Physical Properties
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow. Viscosity is commonly measured in centiPoise (cP). One cP is defined as the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP. A product like honey would have a much higher viscosity -around 10,000 cPs- compared to water. As a result, honey would flow much slower out of a tipped glass than water would. The viscosity of a material can be decreased with an increase in temperature in order to better suit an application
500 mPa.s
Other Properties
Storage Temperature
8°C to 21 °C
Thermal Properties
Thermal Conductivity
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance. Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.
0.1 W/m.K

Additional Information

Technical properties

As supplied

PropertyValueUnitMethod / condition
Specific gravity1.123 deg C
Viscosity500mPa sBrookfield RVT; spindle 3; 20 rpm; 25 deg C
Viscosity450mPa sCone and plate; 25 deg C; 129 s^-1 shear rate; after 180 seconds
Technical properties

Cured material

PropertyValueUnitMethod / condition
Coefficient of thermal expansion80 x 10^-6K^-1ISO 11359-2; cured 24 hours at 23 deg C
Thermal conductivity0.1W/(m K)ISO 8302; cured 24 hours at 23 deg C
Specific heat0.3kJ/(kg K)Cured 24 hours at 23 deg C
Compressive shear strength15N/mm^2ISO 10123; steel pins and collars; cured 24 hours at 23 deg C

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