Quick answer — Loctite 406 essentials
What it is: Loctite 406 is a low-viscosity ethyl cyanoacrylate ("super glue") instant adhesive, purpose-built for fast bonding of plastics and rubbers — including difficult, low-energy substrates that other instant adhesives struggle with.
Cure time: Fixtures in under 5 seconds on rubber, ABS, PVC and aluminium; 20–45 seconds on steel. Full strength develops over 24–72 hours.
What it bonds: Elastomers (nitrile, neoprene), rigid plastics (ABS, PVC, polycarbonate, phenolic), and metals. Doesn't bond well: PP, PE, PTFE without primer · natural rubber without primer · gaps over 0.12 mm.
Loctite 406 vs 401: 406 = low viscosity, optimised for plastics and rubber. 401 = medium viscosity, general-purpose metals and mixed substrates. 480 = rubber-toughened, impact-resistant.
Loctite 406 is a low-viscosity cyanoacrylate instant adhesive, engineered for the substrates that give general-purpose "super glue" the most trouble — rubbers, ABS, PVC, polycarbonate and other low-to-medium energy plastics. Where a general-purpose instant adhesive fixtures unevenly or fails to wet these surfaces properly, 406's lower viscosity and surface-active formulation flow into the joint and cure fast, with a useful spread of published performance data across substrates, temperatures and chemical exposure.
This guide covers what Loctite 406 is, exactly what it bonds and how well, how it compares to 401, 480 and 454, and how to apply, troubleshoot and remove it — sourced from AIMS's own product data and the manufacturer's published technical data sheet, not generic marketing copy.
What Is Loctite 406?
Loctite 406 is an ethyl cyanoacrylate instant adhesive — the same chemistry family as consumer super glue, but formulated and quality-controlled for industrial use. It's part of Henkel's Prism range of industrial instant adhesives, alongside 401 and 480. What sets 406 apart is its low viscosity (around 20 mPa·s, roughly the consistency of water) and a surface-active ingredient that improves adhesion to low-energy plastics and elastomers that standard cyanoacrylates bond poorly.
Like all cyanoacrylates, it cures by reacting with trace surface moisture — not by air-drying or heat curing. No mixing, no clamping equipment, no cure oven required.
Loctite 406 — Quick Reference
| Property | Value |
|---|---|
| Chemistry | Ethyl cyanoacrylate (one-part, moisture-cured) |
| Appearance | Clear to straw-coloured liquid |
| Viscosity | ~20 mPa·s (published TDS range 12–25 mPa·s depending on measurement method) — low viscosity |
| Specific gravity | 1.1 at 25°C |
| Fixture time — steel | 20–45 seconds |
| Fixture time — rubber, ABS, PVC, aluminium | Under 5 seconds |
| Full cure | 24–72 hours |
| Operating temperature | –40°C to +120°C |
| Shear strength — steel | 15.5 N/mm² (2,250 psi) |
| Max gap fill | 0.12 mm — not a gap filler |
| Bonds well | Elastomers (nitrile, neoprene), ABS, PVC, polycarbonate, phenolic, metals |
| Does NOT bond well | PP, PE, PTFE and natural rubber without primer |
| Storage | 2–8°C — performance is affected outside this range |
Fixture Time by Substrate
⚠️ Verify before specifying: Figures below are drawn from the manufacturer's published Technical Data Sheet (fixture time to reach 0.1 N/mm² shear strength, 22°C / 50% RH) and AIMS's own product data. Always confirm against the current TDS before use in a critical or regulated application.
| Substrate | Fixture Time |
|---|---|
| Aluminium (etched) | Under 5 seconds |
| Neoprene | Under 5 seconds |
| Nitrile rubber | Under 5 seconds |
| ABS | Under 5 seconds |
| PVC | Under 5 seconds |
| Phenolic | Under 5 seconds |
| Polycarbonate | 10–20 seconds |
| Steel (degreased) | 20–45 seconds |
The pattern here matters for selection: 406 fixtures almost instantly on rubbers and common rigid plastics — exactly the substrates it's formulated for — and noticeably slower on plain steel, where a general-purpose grade like 401 is the more efficient choice.
Lap Shear Strength by Substrate
Measured to ISO 4587, 24 hours after assembly at 22°C. This is useful data for joint design — most published Loctite content doesn't break it down this far by substrate.
| Substrate | Shear Strength |
|---|---|
| Steel (grit blasted) | 15.5 N/mm² (2,250 psi) |
| Zinc dichromate | 14 N/mm² (2,030 psi) |
| Aluminium (etched) | 12 N/mm² (1,740 psi) |
| Phenolic | 11.3 N/mm² (1,640 psi) |
| Polycarbonate | 9.1 N/mm² (1,320 psi) |
| ABS | 8.8 N/mm² (1,280 psi) |
| PVC | 8.7 N/mm² (1,260 psi) |
| Nitrile rubber | 1.2 N/mm² (175 psi) |
| Neoprene | 1.0 N/mm² (150 psi) |
Reading this table correctly: the lower shear figures on nitrile and neoprene aren't a product weakness — elastomers themselves have much lower internal shear strength than rigid plastics or metal, so the bond in practice is often stronger than the substrate. What matters for rubber bonding is that 406 achieves a genuine, measurable bond at all on these low-energy surfaces, where a standard cyanoacrylate frequently fails to wet the surface and doesn't bond consistently.
Environmental Resistance: Heat and Chemical Exposure
This is the data that determines whether a 406 bond survives in service, not just on the bench.
Hot strength (mild steel, tested at temperature): retains approximately 60% of room-temperature shear strength at 80°C, and approximately 40% at 120°C — consistent with the product's –40°C to +120°C operating range, but a real reminder that strength tapers well before that ceiling.
Heat ageing (1,000 hours continuous exposure, then tested at 22°C):
| Ageing Temperature | Strength Retained After 1,000 hrs |
|---|---|
| 60°C | ~90% |
| 80°C | ~75% |
| 100°C | ~50% |
| 120°C | ~25% |
Chemical exposure (1,000 hours, then tested at 22°C):
| Exposure | Strength Retained |
|---|---|
| Ethanol | ~100% |
| Gasoline | ~95% |
| Water | ~70% |
| Motor oil (40°C) | ~70% |
| High humidity (98% RH, 40°C) | ~45–60% |
What this means for selection: a 406 joint that will sit in continuous high humidity or sustained motor oil contact should be treated as running at roughly two-thirds of its rated bench strength — factor that into the joint design margin rather than assuming full published shear strength applies indefinitely in service.
Loctite 406 vs 401 vs 480 — Which Do You Need?
| Product | Viscosity | Best For | Key Feature | Avoid For |
|---|---|---|---|---|
| 406 | Low (~20 mPa·s) | Rubbers, ABS, PVC, polycarbonate and other difficult plastics | Surface-active ingredient for low-energy plastics and elastomers | Where 401's broader metal performance is the priority; large gaps |
| 401 | Medium (100–120 mPa·s) | Metals, rigid plastics, rubber, porous materials — general purpose | Surface-insensitive; works on chromated & acidic surfaces | PE, PP, PTFE without primer; flexible joints; large gaps |
| 480 | Low-medium (100–200 mPa·s, black) | Dynamic assemblies subject to shock, vibration, or impact | Rubber-toughened; flexible, impact-resistant bond | Where maximum shear strength is needed; visible joints (cures black) |
| 454 | High, thixotropic gel | Vertical/overhead joints, gap-filling repairs, porous materials — wood, paper, leather, fabric | Won't run, drip or wick away; non-drip gel | Rubber-to-rubber bonds needing max shear strength; dynamic loading |
Default choice rule: start with 406 when the substrate is rubber, ABS, PVC, polycarbonate, or another plastic that's given you trouble with a general-purpose instant adhesive before. Move to 401 for metal-to-metal or mixed-substrate work where broad surface tolerance matters more than plastic/rubber optimisation. Move to 480 if the assembly experiences dynamic loading or vibration. Move to 454 gel if the joint is vertical, overhead, gap-filling, or on a porous material such as wood, paper, leather or fabric. Add Loctite SF 770 primer if the substrate is PE, PP, or PTFE regardless of which adhesive you choose.
Read the full Loctite 401 Guide, Loctite 480 Guide, or Loctite 454 Guide for each grade's own detailed spec sheet.
When to Use Primer or Activator With Loctite 406
Loctite SF 770 — Polyolefin Primer
Use SF 770 when bonding polyethylene (PE), polypropylene (PP), PTFE, or other low-energy plastics that 406 alone won't wet reliably. Apply SF 770 by brush to one bond surface, allow it to dry for around 30 seconds, then apply Loctite 406 to the primed surface and assemble immediately.
Loctite 7452 Tak Pak Accelerator
Use the accelerator when cure needs to be sped up further — on larger gaps approaching the 0.12 mm limit, in low-humidity conditions, or on substrates where natural moisture-triggered cure is slower than the job allows. Apply to one bond surface, apply 406 to the other, and assemble immediately. As with any accelerator, using it on a large gap can trade off some ultimate bond strength for speed — for joints where maximum strength matters more than assembly speed, allow natural cure instead.
💡 Primer and accelerator are not the same job. SF 770 modifies a low-energy surface so it can be wetted by the adhesive at all. The 7452 accelerator speeds up the cure reaction on a surface that already accepts the adhesive. Using accelerator on unprimed PE or PP will not fix an adhesion problem — you need the primer first.
How to Apply Loctite 406
- Clean both surfaces. Remove oil, grease, dust, and release agents with Loctite SF 7063 general purpose cleaner or isopropanol. Dry completely — surface contamination is the most common cause of bond failure.
- Check the fit. The joint gap must be under 0.12 mm. 406 is not a gap filler — address poor-fitting surfaces before bonding, not with extra adhesive.
- Apply primer if the substrate needs it. PE, PP and PTFE need Loctite SF 770 primer first — see above.
- Apply adhesive to one surface only. A thin film is sufficient. Excess adhesive slows cure, reduces strength, and increases the risk of white residue (bloom).
- Assemble immediately and hold firm contact. 5–10 seconds of firm pressure. Do not slide the parts against each other after contact is made.
- Respect fixture time before handling. Rubbers, ABS, PVC and aluminium fixture in under 5 seconds; steel needs 20–45 seconds. Avoid loading the joint for at least 15 minutes, and allow 24–72 hours before full design load.
- Remove excess adhesive promptly. Uncured 406 wipes off with Loctite SF 7063 or acetone before it cures.
⚠️ Skin contact: Cyanoacrylate bonds skin immediately. Wear nitrile gloves. If skin bonding occurs, soak in warm soapy water and gently peel apart — don't pull forcefully. Acetone applied after soaking helps separate bonded skin. Eye contact requires immediate flushing with water and medical review.
Common Failures and How to Fix Them
Poor adhesion on PP, PE or PTFE
Cause: these are low-energy surfaces that cyanoacrylate can't wet reliably without help, even 406's surface-active formulation.
Fix: apply Loctite SF 770 primer first, allow it to flash off, then apply 406 immediately.
Weak bond on natural rubber
Cause: natural rubber's surface chemistry resists cyanoacrylate wetting more than synthetic elastomers like nitrile or neoprene, which 406 is specifically formulated for.
Fix: prime the surface, or consider whether a flexible epoxy or polyurethane adhesive is a better fit for the specific rubber compound in question.
White residue (bloom) around the joint
Cause: excess adhesive vapour reacting with atmospheric moisture and depositing as white polymer residue nearby.
Fix: use less product — a thin film is sufficient. Improve ventilation. Bloom is cosmetic, not structural.
Bond fails under vibration or impact
Cause: 406 produces a relatively rigid bond line; it isn't designed for dynamic, high-shock loading.
Fix: switch to Loctite 480 (rubber-toughened, impact-resistant) for assemblies subject to vibration or shock loading.
Strength lower than expected after time in service
Cause: the joint has been in continuous heat, humidity, oil, or water exposure — the environmental resistance data above shows meaningful strength loss under sustained exposure, particularly above 100°C or in high humidity.
Fix: design joints with this de-rating in mind rather than assuming bench-test strength applies indefinitely in a hot, wet, or oil-exposed environment.
Removing Loctite 406
Mechanical removal (metal or rigid assemblies): apply heat with a hot air gun. Cured cyanoacrylate softens with heat — once softened, pry apart with a flat tool. Clean and degrease the bond area with Loctite SF 7063 before re-bonding.
Uncured product: wipes off cleanly with Loctite SF 7063 or acetone before it cures.
AIMS doesn't currently stock a dedicated chemical cyanoacrylate debonder — for a fully cured bond on a substrate that can't take heat (some plastics, coated surfaces), mechanical separation or replacement of the bonded part is the practical option; check with AIMS if a specific debonding chemical is needed for your application.
Typical Applications in Industrial Settings
Rubber and plastic component assembly
Bonding gaskets, seals, grommets and rubber feet to housings. Assembling ABS and PVC enclosures, covers and ducting. Polycarbonate glazing and guard bonding where a fast, near-invisible bond line is wanted.
Maintenance and repair
Reattaching rubber bumpers and anti-vibration mounts. Repairing cracked plastic housings and covers. Bonding replacement seals and gaskets in the field, where fast fixture on rubber matters more than maximum metal-to-metal strength.
Manufacturing and assembly
Fixture bonding of rubber and plastic components in production, ahead of a secondary mechanical fastening or moulding step. Sensor and instrument housings where the bond line needs to stay thin and close to invisible.
What Loctite 406 is not suited for
Structural, load-bearing joints (use structural epoxy). Joints loaded in peel — cyanoacrylates are weak in peel regardless of grade. Large gaps over 0.12 mm (up to 0.25 mm, consider Loctite 454 gel; beyond that, use epoxy). Dynamic, high-vibration assemblies (use 480 instead). Continuous immersion in water, oil or fuel without accounting for the strength de-rating shown above.
Loctite 406 Storage and Shelf Life
| Condition | Guidance |
|---|---|
| Storage temperature | 2–8°C — performance is adversely affected outside this range |
| Opened bottle | Keep the cap tightly sealed between uses |
| Best humidity for application | 40–60% RH — lower humidity slows cure, higher humidity can reduce final strength |
| Keep away from | Direct sunlight, heat sources, and prolonged exposure outside the 2–8°C range |
If the adhesive is stringing, gelling, or producing noticeably poorer bonds than expected, the product has likely degraded from incorrect storage and should be replaced — don't rely on out-of-condition product for a joint that matters.
Loctite 406 is one of several instant adhesive grades stocked at AIMS. For general-purpose metal and mixed-substrate bonding, see the Loctite 401 Guide. For a full comparison across adhesive families — contact adhesive, epoxy, anaerobic threadlockers, structural acrylic, and RTV silicone — see the Industrial Adhesive Types Guide.
Frequently Asked Questions
What is Loctite 406 used for?
Loctite 406 is a low-viscosity instant adhesive purpose-built for fast bonding of plastics and rubbers — particularly ABS, PVC, polycarbonate, phenolic, nitrile and neoprene, substrates that give general-purpose cyanoacrylates more trouble. Typical uses include gasket and seal bonding, plastic housing and enclosure assembly, rubber component attachment, and any close-fitting joint where a thin, near-invisible bond line on plastic or rubber is needed.
What is the difference between Loctite 401 and Loctite 406?
401 is a medium-viscosity, surface-insensitive general-purpose cyanoacrylate — it bonds metals, rigid plastics, rubber and porous materials, and performs well on acidic or chromated metal surfaces. 406 is a lower-viscosity formula with a surface-active ingredient specifically for difficult-to-bond plastics (ABS, PVC, polycarbonate) and elastomers. If the job is mostly metal or mixed substrates, 401 is the more versatile choice. If it's rubber or a difficult plastic, 406 is the better-performing option.
How long does Loctite 406 take to cure?
Fixture time depends heavily on substrate: under 5 seconds on rubber, ABS, PVC, phenolic and aluminium; 10–20 seconds on polycarbonate; 20–45 seconds on steel. Full strength and full chemical/solvent resistance develop over 24–72 hours. Don't load a joint to full design strength before that window has passed.
What is the shear strength of Loctite 406?
It varies significantly by substrate: 15.5 N/mm² on grit-blasted steel, 12 N/mm² on etched aluminium, 9.1 N/mm² on polycarbonate, 8.8 N/mm² on ABS, 8.7 N/mm² on PVC, and around 1.0–1.2 N/mm² on neoprene and nitrile rubber. The lower rubber figures reflect the substrate's own lower shear strength, not a weak bond — the adhesive itself achieves reliable wetting and cure on these surfaces where standard cyanoacrylates often fail outright.
Can Loctite 406 bond rubber?
Yes — this is one of 406's core applications. It bonds nitrile rubber and neoprene reliably, which is exactly the gap it's formulated to fill compared with general-purpose grades. Natural rubber is more resistant to cyanoacrylate bonding generally; for natural rubber specifically, priming the surface or considering a flexible epoxy alternative is worth checking first.
Can Loctite 406 bond polycarbonate, ABS or PVC?
Yes, all three are core substrates for 406, with published shear strengths of 9.1 N/mm² (polycarbonate), 8.8 N/mm² (ABS) and 8.7 N/mm² (PVC), and fixture times of 20 seconds or less on all three. This is one of the main reasons to reach for 406 over a general-purpose grade when the job is plastic.
What temperature can a Loctite 406 bond withstand?
The rated operating range is –40°C to +120°C, but strength tapers well before that ceiling: expect roughly 60% of room-temperature strength at 80°C and around 40% at 120°C. For continuous service near the top of that range, factor the de-rating into the joint design rather than assuming full bench-test strength applies.
Does Loctite 406 need primer?
Not for its core substrates — rubber, ABS, PVC, polycarbonate and phenolic bond well without primer. Primer (Loctite SF 770) is needed for polyethylene, polypropylene and PTFE, which resist cyanoacrylate bonding at a surface-energy level that 406's formulation alone doesn't overcome.
What is the difference between Loctite 406 and 480?
406 produces a relatively rigid bond optimised for plastics and rubber under static loading. Loctite 480 is rubber-toughened and flexible, built to survive shock, vibration and dynamic loading — at the cost of some raw shear strength, and it cures black rather than clear. Choose 406 for a strong, low-visibility static bond on plastic or rubber; choose 480 where the joint will be shaken, knocked or flexed in service.
What is the maximum gap Loctite 406 can fill?
0.12 mm. Like all cyanoacrylates, 406 is not a gap-filling adhesive — it's designed for close-fitting joints, and performance drops off as the gap increases. For looser-fitting joints or larger gaps, an epoxy adhesive is the more appropriate choice.
How should Loctite 406 be stored?
Store between 2°C and 8°C — storage outside this range can adversely affect the product's properties. Keep the cap tightly sealed between uses, away from direct sunlight and heat sources. Best application results come at 40–60% relative humidity; very low humidity slows cure, and very high humidity can reduce final bond strength.
Is Loctite 406 the same as super glue?
Same underlying chemistry — both are ethyl cyanoacrylate — but 406 is an industrial-grade formulation with defined, published viscosity, shear strength, temperature and chemical-resistance data, plus a surface-active ingredient targeted at difficult plastics and rubbers. Consumer super glue carries none of that published performance data and is formulated for general household use rather than a specific substrate class.
Does Loctite 406 resist chemicals, oil or fuel?
Reasonably well, but not indefinitely. After 1,000 hours of continuous exposure at 22°C, published data shows around 100% strength retained against ethanol, 95% against gasoline, and around 70% against both water and motor oil. High humidity (98% RH at 40°C) is the harshest tested condition, retaining roughly 45–60% of strength. Build this de-rating into the design for any joint that sees sustained chemical exposure.
How do I remove or debond Loctite 406?
For metal or heat-tolerant assemblies, apply heat with a hot air gun — the cured adhesive softens and the joint can be pried apart, then cleaned with Loctite SF 7063 before re-bonding. AIMS doesn't currently stock a dedicated chemical cyanoacrylate debonder, so for heat-sensitive substrates, mechanical separation or replacing the bonded part is the practical route.
Where can I buy Loctite 406 in Australia?
AIMS Industrial stocks Loctite 406 Prism Surface Insensitive Instant Adhesive with fast Australia-wide delivery.
People Also Ask — Loctite 406
Q: What materials is Loctite 406 designed to bond?
It's designed for elastomers, resins and difficult-to-bond plastic substrates, as well as general plastics and rubbers.
Q: How fast does Loctite 406 fixture on steel?
Published fixture time on degreased steel is 20–45 seconds; AIMS's own product data cites 30 seconds as a representative figure within that range.
Q: Is Loctite 406 stronger than Loctite 401?
Not universally — it depends on the substrate. On steel, 401's broader general-purpose formulation and 406 both achieve high shear strength in the 14–16 N/mm² range. On rubber and difficult plastics, 406 achieves a reliable bond where 401 may not wet the surface as consistently — so "stronger" depends on what you're bonding, not a single number.
Q: Can Loctite 406 be used on silicone?
Not reliably. Silicone is an extremely low-energy surface that resists cyanoacrylate bonding even with 406's surface-active formulation. A silicone-specific adhesive or an RTV silicone product is the more reliable choice for bonding to silicone rubber.
Related Guides
- Loctite 401 Guide — the general-purpose grade, for metals and mixed-substrate work
- Loctite 480 Guide — rubber-toughened, for shock and vibration
- Loctite 454 Guide — gel, for gap-filling, vertical work and porous materials
- The Complete Loctite Application Guide — overview of all Loctite product families
- Industrial Adhesive Types Guide — epoxy, RTV, structural acrylic and anaerobic adhesives compared
- Epoxy Adhesive Guide — for structural, gap-filling and load-bearing bonds outside 406's range
Shop Loctite 406 Instant Adhesive →
All technical specifications should be verified against the current Loctite Technical Data Sheet before use in structural, safety-critical, or regulated applications. Contact the AIMS Industrial team if you need help specifying the right instant adhesive for your application.