Loctite 243 — the medium-strength threadlocker that holds, and lets go.
One-component anaerobic threadlocker for bolts, nuts, and studs. Locks against shock and vibration, seals the thread path against leaks, and still comes apart with standard hand tools. Blue, thixotropic, no mixing — works on stainless steel, brass, and plated surfaces. As of August 2026, a standard pack is ₹531 incl GST from our Ghaziabad warehouse.
Not epoxy. Not a sealant. A threadlocker with a split personality — on purpose.
Loctite 243 by Henkel is a medium-strength anaerobic threadlocker based on dimethacrylate ester chemistry. It cures only when confined in the absence of air between close-fitting metal surfaces — so it stays liquid in the bottle and locks exactly where you put it.
Locks against vibration
Prevents loosening and leakage from shock and vibration. Its thixotropic body stops the liquid from migrating after you apply it.
Comes apart with hand tools
Medium strength means normal disassembly. Lock the bolt, seal the thread, and still remove it later with standard hand tools.
Survives the tough jobs
Works on active metals (brass, copper) and passive substrates (stainless steel, plated surfaces), tolerates oil contamination, and holds up to 200°C.
Complete Specifications from Henkel TDS
| Property | Value | Test Method |
|---|---|---|
| Technology | Acrylic | - |
| Chemical type | Dimethacrylate ester | - |
| Appearance (uncured) | Blue — positive fluorescence under UV | Visual |
| Components | One component — requires no mixing | - |
| Viscosity at 25°C | 2,000 mPa·s (cP), medium, thixotropic | Brookfield RVT, Spindle 20, 1.08 rpm |
| Viscosity at 25°C (Cone & Plate) | 350 mPa·s (cP) | Cone 35/2 @ 129 s⁻¹ |
| Specific gravity at 23°C | 1.08 | - |
| Cure mechanism | Anaerobic — cures in absence of air on metal | - |
| Strength | Medium | - |
| Compressive shear strength | 7.6 N/mm² (1,100 psi) | ISO 10123 — steel pins/collars, 1 week @ 23°C |
| Glass transition temperature | 100°C | ISO 11359-2 |
| Coefficient of thermal expansion | 80 x 10⁻⁶ K⁻¹ (below Tg) / 90 x 10⁻⁶ K⁻¹ (above Tg) | ISO 11359-2 |
| Thermal conductivity | 0.1 W/(m·K) | ISO 8302 |
| Temperature performance | Cold tested to -75°C; heat aging up to 200°C | - |
| Storage | 8°C to 21°C optimum (below 8°C or above 28°C adverse) | - |
Which Job Should You Use Loctite 243 For?
243 is a medium-strength threadlocker, not a retaining compound and not an epoxy. Pick your job below to see if it fits.
| You want | Buy | Why | Price |
|---|---|---|---|
| Lock threaded fasteners that must come apart again | Loctite 243 | Medium strength — 26 N·m M10 breakaway, yet removable with hand tools | ₹531 |
| Seal threaded joints against leakage | Loctite 243 | 360° bead on leading threads seals the thread path; resists oil, fuel, brake fluid | ₹531 |
| Lock fasteners on stainless steel or plated surfaces | Loctite 243 | Formulated for passive substrates; tolerates oil contamination; activator for fast cure | ₹531 |
| Work in hot environments | Loctite 243 | Heat aging up to 200°C, cold strength to -75°C | ₹531 |
Not for: Pure oxygen systems, chlorine or strong oxidizers, and plastics (thermoplastics can stress-crack). If you need epoxy adhesives instead, see our epoxy resin guide or Bondone Clear Cast.
Application Guide
Clean the threads
Clean all external and internal surfaces with a cleaning solvent and allow them to dry. If the cure speed is too slow, apply the appropriate activator and let it dry. Shake the product thoroughly before use, and do not let the tip touch metal during application or it will clog.
Thru holes
Apply several drops onto the bolt at the nut engagement area.
Blind holes
Apply several drops to the lower third of the internal threads or the bottom of the blind hole.
Sealing applications
Apply a 360° bead to the leading threads of the male fitting, leaving the first thread free, and force the material into the threads. For larger threads, also apply a 360° bead on the female threads.
Assemble and tighten
Assemble and tighten as required. The product cures anaerobically — it will not cure until the air is excluded between the threads, so speed of assembly is not critical.
Disassembly and cleanup
Remove with standard hand tools. If hand tools fail because of excessive engagement length, apply localized heat of approximately 250°C and disassemble while hot. Remove cured product by soaking in a solvent combined with mechanical abrasion such as a wire brush.
Price & Availability
Bulk cartons and repeat supply contracts priced on request
Price valid until March 31, 2027. Includes one standard 50 ml pack of Loctite 243. Bulk packs and regular supply contracts available — WhatsApp for the current bulk rate and stock position.
UPI, bank transfer, or credit card invoice via Razorpay link. No COD. GST invoice provided. For enquiries, WhatsApp Jobin directly.
We ship PAN India from our Ghaziabad warehouse — typically 2-5 business days via Delhivery, Blue Dart, or surface transport for bulk. Orders before 12 PM go out same day. All sales are final; see our refund policy.
Need Loctite 243 today?
WhatsApp Jobin directly. He will confirm stock, share the Henkel TDS, and arrange dispatch from Ghaziabad within 24 hours.
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