Product details
| Grade | Loctite 242 |
| Strength | Medium strength |
| Colour | Blue |
| Family | Threadlockers |
| Brand | Loctite (Henkel) |
| Stock | Held in Dubai — buy one or bulk |
Pack sizes
Prices on request. Tell us the quantity you need.
Check stockWhat Loctite 242 is for
The original blue medium-strength threadlocker. It locks and seals threaded fasteners against shock and vibration, while still allowing normal disassembly with standard hand tools. Henkel positions it particularly for less active substrates such as plated surfaces. It is thixotropic, so it stays on the thread rather than running off.
Key features
- Medium strength — comes apart with ordinary hand tools
- Suited to less active substrates such as plated surfaces
- Thixotropic — resists migration after application
- Tested to the lot requirements of Mil-S-46163A (a regional approval)
- Fluoresces under UV light for inspection
- Holds 100% of initial strength after 1,000 h in motor oil at 125°C
Typical applications
- General machinery
- Maintenance fasteners
Technical data
Uncured material
| Technology | Acrylic |
| Chemical type | Dimethacrylate ester |
| Appearance | Blue liquid |
| Fluorescence | Positive under UV light |
| Components | One component — no mixing |
| Cure | Anaerobic; secondary cure by activator |
| Viscosity | Medium, thixotropic |
| Viscosity, Brookfield RVT 25°C | Spindle 3 at 20 rpm: 900–1,400 mPa·s |
| Specific gravity at 25°C | 1.1 |
| Lubricity, K value (ASTM D5648) | −10 to 10 |
Torque performance
3/8 × 16 steel nuts (grade 2) and bolts (grade 5) unless stated, at 22°C.
| Breakaway torque after 1 hour | 5.6–17 N·m (50–150 lb·in) |
| Prevail torque after 1 hour | 1.7–6.8 N·m (15–60 lb·in) |
| Breakaway torque after 24 hours | 7.9–17 N·m (70–150 lb·in) |
| Breakaway torque, M10 black oxide steel | 8–19 N·m (71–168 lb·in) |
| Prevail torque after 24 hours | 2.8–6.8 N·m (25–60 lb·in) |
| Breakaway on zinc nuts and bolts | 2.3–6.8 N·m (20–60 lb·in) |
| Breakaway on cadmium nuts and bolts | 1.1–6.8 N·m (10–60 lb·in) |
Chemical resistance
Breakloose torque as a percentage of initial strength after ageing.
| Environment | °C | 100 h | 500 h | 1,000 h |
|---|
| Motor oil (MIL-L-46152) | 125 | 100% | 100% | 100% |
| Unleaded petrol | 22 | 100% | 100% | 95% |
| Brake fluid | 22 | 100% | 100% | 100% |
| Ethanol | 22 | 100% | 100% | 95% |
| Acetone | 22 | 100% | 100% | 85% |
| Water / glycol 50:50 | 87 | 80% | 75% | 70% |
Cured material
| Heat ageing data published to | 150°C |
| Hot strength plotted to | 150°C |
How to use it
- Clean all threads, internal and external, with a Loctite cleaning solvent and allow to dry.
- Shake the bottle thoroughly before use.
- Do not let the nozzle touch metal — it makes the product cure in the tip.
- Thru holes: apply several drops onto the bolt at the nut engagement area.
- Blind holes: apply several drops down the internal threads to the bottom of the hole.
- Sealing: apply a 360° bead to the leading male threads, leaving the first thread free, and work it into the thread roots.
- Assemble and tighten to the specified torque within the fixture time.
Handling and storage
- Not recommended for pure oxygen or oxygen-rich systems.
- Not a sealant for chlorine or other strong oxidising materials.
- Not normally recommended on plastics — thermoplastics can stress-crack.
- On passive metals (stainless, aluminium, plated) or below 5°C, use Loctite SF 7471 or SF 7649 activator to bring the cure speed up.
- Store unopened and dry. Henkel gives optimal storage as 8°C to 21°C; outside 8–28°C the product properties can be affected.
- Do not return decanted product to the original container.
Loctite 242 or 243?
Both are blue medium-strength grades that disassemble with hand tools. 243 is the newer formulation: it cures more robustly on passive substrates such as stainless steel without an activator, and tolerates light oil contamination — cutting, lubricating and anti-corrosion fluids — which 242 does not. If the threads are degreased and the substrate is active, either works. If they are oily or stainless, specify 243.
Always read the current technical and safety data before use —
ask us and we'll send it with your quotation.
