🧪 Loctite 406 Instant Adhesive 20g – Ultra-Low Viscosity Super Glue for Plastics & Rubber

Loctite® 406 Instant Adhesive (20g) is a high-performance cyanoacrylate designed specifically for fast bonding of plastics and elastomers, including difficult substrates like EPDM rubber. It features ultra-low viscosity (20 cP), making it ideal for tight-fitting assemblies and capillary action in fine gaps.

When used with Loctite® 770 or 7239 primer, it enhances adhesion on low-energy surfaces like polyethylene and polypropylene. Whether you're working on industrial assembly, consumer product repair, or component bonding, Loctite 406 delivers quick, strong, and reliable results.

✅ Key Features:

• Ultra-low viscosity: 20 mPa·s – ideal for tight tolerance parts

• Bonds rubber, plastics, and difficult-to-bond elastomers

• Fixture time in seconds for high-speed assembly

• High shear strength: 3,200 psi on grit-blasted steel

• Works in temperatures from -65°F to 250°F (-54°C to 120°C)

• Compatible with Loctite Primers for improved bonding on polyolefins

• Clear, colorless finish for clean, invisible bonds

📦 Product Specifications:

• Brand: Loctite

• Model: 406

• Weight: 20 grams

• Curing Method: Humidity-activated

• Viscosity: 20 cP

• Temperature Range: -65°F to 250°F

• Primary Substrates: Rubber, plastics, elastomers

• Appearance: Ultra-clear

• Application Type: Precision bonding / fast repairs

🔧 Applications:

• Rubber sealing and gasket bonding

• Plastic part assembly in appliances or electronics

• Automotive interior trim bonding

• O-ring and elastomer bonding

• EPDM bonding with primer

• Ideal for use in fast-paced manufacturing and repair operations

• Shear Strength, Grit Blasted Steel : 3200 psi
• Temperature : -65 - 250 °F
• Viscosity : 20 mPa.s (cP) Brookfield
• Key Substrates : Plastics and Rubbers
• Color : Clear: Ultra Clear
• Curing Type : Humidity
• Application : Bonding

LOCTITE® 406 is an instant adhesive designed especially for the fast bonding of plastics and rubbers. This product offers exceptionally low viscosity. When combined with LOCTITE primers for cyanoacrylates, it can also be used on difficult-to-bond plastics.

• Rapid bonding of plastic & rubber, including EPDM
• LOCTITE 770 or LOCTITE 7239 primer improves adhesion of difficult-to-bond substrates

 
LOCTITE®
406™ is designed for bonding of plastics and
elastomeric materials where very fast fixturing is required.

Commercial Item Description A-A-3097:

LOCTITE®
406™ has been qualified to Commercial Item
Description A-A-3097. Note: This is a regional approval.
Please contact your local Technical Service Center for more
information and clarification.

TYPICAL CURING PERFORMANCE

Under normal conditions, the atmospheric moisture initiates the
curing process. Although full functional strength is developed
in a relatively short time, curing continues for at least 24 hours
before full chemical/solvent resistance is developed.

Cure Speed vs. Substrate

The rate of cure will depend on the substrate used. The table
below shows the fixture time achieved on different materials
at 22 °C / 50 % relative humidity. This is defined as the time to
develop a shear strength of 0.1 N/mm².

Cure Speed vs. Bond Gap

The rate of cure will depend on the bondline gap. Thin bond
lines result in high cure speeds, increasing the bond gap will
decrease the rate of cure.

Cure Speed vs. Humidity

The rate of cure will depend on the ambient relative
humidity. The best results are achieved when the relative
humidity in the working environment is 40% to 60% at 22°C.
Lower humidity leads to slower cure. Higher humidity
accelerates it, but may impair the final strength of the bond.

Cure Speed vs. Activator

Where cure speed is unacceptably long due to large gaps,
applying activator to the surface will improve cure speed.
However, this can reduce ultimate strength of the bond and
therefore testing is recommended to confirm effect.

GENERAL INFORMATION

This product is not recommended for use in pure oxygen
and/or oxygen rich systems and should not be selected as
a sealant for chlorine or other strong oxidizing materials.
For safe handling information on this product, consult the
Safety Data Sheet (SDS).

Directions for use:

1. Bond areas should be clean and free from grease. Clean
   all surfaces with a Loctite®
   cleaning solvent and allow to
   dry.
2. To improve bonding on low energy plastic surfaces,
   Loctite® Primer may be applied to the bond area. Avoid
   applying excess Primer. Allow the Primer to dry.
3. LOCTITE® Activator may be used if necessary. Apply it to
   one bond surface (do not apply activator to the primed
   surface where Primer is also used). Allow the Activator to
   dry.
4. Apply adhesive to one of the bond surfaces (do not apply
   the adhesive to the activated surface). Do not use items
   like tissue or a brush to spread the adhesive. Assemble
   the parts within a few seconds. The parts should be
   accurately located, as the short fixture time leaves little
   opportunity for adjustment.
5. LOCTITE®
   Activator can be used to cure fillets of product
   outside the bond area. Spray or drop the activator on the
   excess product.
6. Bonds should be held fixed or clamped until adhesive has
   fixtured.
7. Product should be allowed to develop full strength before
   subjecting to any service loads (typically 24 to 72 hours
   after assembly, depending on bond gap, materials and
   ambient conditions).

Loctite Material Specification

LMS dated December-22, 2011. Test reports for each batch
are available for the indicated properties. LMS test reports
include selected QC test parameters considered appropriate to
specifications for customer use. Additionally, comprehensive
controls are in place to assure product quality and
consistency. Special customer specification requirements may
be coordinated through Henkel Quality.

Storage

Store product in the unopened container in a dry location.
Storage information may be indicated on the product container
labeling.
Optimal Storage: 8 °C to 21 °C. Storage below 8 °C or
greater than 28 °C can adversely affect product properties.
Material removed from containers may be contaminated during
use. Do not return product to the original container. Henkel
Corporation cannot assume responsibility for product which
has been contaminated or stored under conditions other than
those previously indicated. If additional information is required,
please contact your local Technical Service Center or
Customer Service Representative.