LOCTITE 380 Rubber-Toughened Instant Adhesive for Metal, Rubber and Plastic Bonding

LOCTITE 380 Rubber-Toughened Instant Adhesive Benefits

LOCTITE 380 Rubber-Toughened Instant Adhesive combines rapid fixture development and mechanical toughness. Henkel lists an approximate fixture time of 90 seconds, helping production teams move assembled parts to the next process with less waiting. The black color improves dispensing visibility and provides a discreet bond line on dark components and housings.

The toughened chemistry helps absorb and distribute stress around the joint. This characteristic is valuable when bonded parts experience vibration, shock, handling or thermal expansion differences. The adhesive provides strong peel, impact, and shear performance while retaining the convenience of a ready-to-use cyanoacrylate.

Applications for LOCTITE 380 Rubber-Toughened Instant Adhesive

This product is designed for fitted components made from metals, plastics, rubbers, and elastomers. Typical applications include bonding rubber seals to metal housings, attaching elastomeric components, assembling automotive trim, securing electronic parts, joining appliance components, fixing small mechanical parts, and completing maintenance repairs.

Its low viscosity is best suited to narrow gaps and close-fitting surfaces. Henkel lists a gap-fill capability of approximately 0.1 mm, while the technical data recommends thin bond lines near 0.05 mm for optimum performance. Wider gaps can slow curing and may require a compatible LOCTITE activator, although activation can reduce final bond strength and should be validated before production use.

LOCTITE 380 Rubber-Toughened Instant Adhesive Technical Properties

The uncured adhesive is a black ethyl cyanoacrylate liquid with a typical specific gravity of approximately 1.1 at 25°C. Published viscosity ranges from 100 to 800 mPa·s under the stated Brookfield test method. Fixture time varies by substrate, with representative values of 60 to 120 seconds on degreased steel, 10 to 30 seconds on aluminum, and 15 to 25 seconds on neoprene or nitrile rubber.

After 24 hours at 22°C, typical lap-shear strength is approximately 26 N/mm² on grit-blasted steel and 18 N/mm² on etched aluminum. Henkel also reports strong adhesion on ABS, PVC, polycarbonate, phenolic, neoprene, and nitrile substrates. Henkel lists temperature resistance up to 107°C. These figures are typical laboratory values rather than guaranteed purchase specifications.

How to Apply LOCTITE 380 Rubber-Toughened Instant Adhesive

Clean bonding surfaces thoroughly and remove oil, grease, dust, oxidation, moisture, mold-release agents, and loose contamination. Apply a small amount to one surface, assemble the parts immediately, and hold or clamp them until fixture strength develops. Accurate positioning is important because the fast curing process leaves limited adjustment time.

For difficult low-surface-energy plastics, apply LOCTITE SF 770 Primer and allow it to dry before adhesive dispensing. When curing is too slow, LOCTITE SF 7452 or SF 7455 Activator may be evaluated on an unprimed surface. Avoid excessive adhesive because thick layers can delay curing and increase white blooming around the bond area.

Why Buy LOCTITE 380 Rubber-Toughened Instant Adhesive?

LOCTITE 380 Rubber-Toughened Instant Adhesive offers fast assembly, strong close-fitting adhesion, impact resistance, improved peel strength, and convenient one-part processing. It is a practical professional commercial choice for automotive, electronics, appliance, rubber-to-metal, and industrial component bonding where a standard brittle instant adhesive may not provide sufficient toughness.

Store unopened containers in a dry refrigerated location according to Henkel guidance and review the Safety Data Sheet before handling. Consult the official LOCTITE 380 Technical Data Sheet before qualification. Explore our industrial instant adhesives for additional flexible, low-viscosity, gel, and high-temperature bonding solutions.