LOCTITE EA 3942
Harmonization Code : 3214.10.00 | Putty and other mastics | Resin cements, caulking compounds and other mastics

Main features
- 900-1,600 mPa s Dispensing
- Sub-5-Second UV Fixture
- UV-Fluorescent Assembly Inspection
Product Description
LOCTITE AA 3942 is a one-part, medium-viscosity UV and visible-light acrylic adhesive for disposable medical-device assembly. It is specifically designed for bonding stainless-steel cannulae into hubs, syringes and lancets and also bonds the specified plastic, glass and metal substrates. The 900 to 1,600 mPa s viscosity at 25 deg C supports controlled needle-assembly dispensing, while fixture develops in less than 5 seconds under the stated 365 nm UV conditions. UV fluorescence supports adhesive-presence inspection, and the cured material reaches Shore D 76 with 29 N/mm^2 tensile strength under the stated cure.
Key features
- Controlled needle dispensing: Typical viscosity is 900 to 1,600 mPa s at 25 deg C.
- Fast UV fixture: Fixture develops in less than 5 seconds at 30 mW/cm^2 and 365 nm on glass.
- UV inspection: Positive fluorescence supports adhesive-presence checks in bonded assemblies.
Applications
Applications include stainless-steel cannula bonding in hubs, syringes and lancets, plus documented plastic, glass and metal bonding for disposable medical-device assembly.
Technical Specifications
No specifications available.
Additional Information
As-supplied properties
Typical uncured-product values at 25 deg C unless otherwise stated.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Transparent to hazy liquid | Free of undissolved solids | |
| UV fluorescence | Positive | Inspection under UV light | |
| Specific gravity | 1.03 | At 25 deg C | |
| Gardner color | 3 or less | Typical limit | |
| Viscosity | 900 to 1,600 | mPa s | Brookfield RVT, spindle 2, 20 rpm, 25 deg C |
Final-state properties
Typical cured-material values after 100 mW/cm^2 at 365 nm for 30 seconds using an electrodeless D bulb, unless otherwise stated.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Shore hardness | 76 | Durometer D | ISO 868 |
| Linear shrinkage | 2.0 | % | Cured material |
| Elongation at break | 15 | % | ISO 527-3 |
| Glass transition temperature | 55 | deg C | ASTM E 228 |
| Tensile strength | 29 | N/mm^2 | ISO 527-3 |
| Tensile modulus | 986 | N/mm^2 | ISO 527-3 |
| UV depth of cure | At least 1.5 | mm | 100 mW/cm^2 at 365 nm for 10 seconds, electrodeless D bulb |
| Block shear strength | 11.1 | N/mm^2 | Polycarbonate to polycarbonate, 100 mW/cm^2 at 365 nm for 10 seconds |





















