Product details
| Grade | Loctite 603 |
| Strength | High strength |
| Colour | Green |
| Family | Retaining compounds |
| 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 603 is for
The thin, oil-tolerant retaining compound. At 100–150 mPa·s it flows into tight slip fits that a thick grade like 638 simply cannot enter, and Henkel specifies it particularly where consistently clean surfaces cannot be assured — which is most of the time in a working machine shop. High strength at ≥22.5 N/mm², and ≥13.5 N/mm² after thirty minutes.
Key features
- Very low viscosity — enters tight slip fits, 100–150 mPa·s
- Formulated for surfaces that cannot be reliably cleaned
- High strength: ≥22.5 N/mm² after 24 hours
- ≥13.5 N/mm² after just 30 minutes
- NSF registered Category P1 for food processing areas (a regional approval)
- Full strength retained in motor oil at 125°C to 1,000 hours
- Typical use: roller bearings and oil-impregnated bushings into housings
Technical data
Uncured material
| Technology | Acrylic |
| Chemical type | Urethane methacrylate |
| Appearance | Green liquid |
| Fluorescence | Positive under UV light |
| Components | One component — no mixing |
| Cure | Anaerobic; secondary cure by activator |
| Viscosity, Brookfield RVT 25°C | Spindle 1 at 20 rpm: 100–150 mPa·s |
| Viscosity, EN 12092 MV 25°C | 90–180 mPa·s at 277 s⁻¹ |
| Viscosity class | Low |
| Specific gravity at 25°C | 1.1 |
Strength
Steel pins and collars at 22°C. Cure graphs are published at gaps of 0.05, 0.15 and 0.2 mm — the tighter the fit, the faster it develops strength.
| Compressive shear strength after 30 min (ISO 10123) | ≥13.5 N/mm² (1,960 psi) |
| Compressive shear strength after 24 h (ISO 10123) | ≥22.5 N/mm² (3,260 psi) |
Chemical resistance
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% | 90% | 85% |
| Brake fluid | 22 | 100% | 90% | 80% |
| Water / glycol 50:50 | 87 | 100% | 90% | 80% |
| Ethanol | 22 | 100% | 100% | 75% |
| Acetone | 22 | 90% | 90% | 90% |
Cured material
| Coefficient of thermal expansion (ISO 11359-2) | 80 × 10⁻⁶ K⁻¹ |
| Thermal conductivity (ISO 8302) | 0.1 W/(m·K) |
| Specific heat | 0.3 kJ/(kg·K) |
| Heat ageing data published at | 120°C and 150°C |
How to use it
- Clean all surfaces, external and internal, with a Loctite cleaning solvent and allow to dry.
- On inactive metals, or where large gaps are present, use an activator and allow to dry.
- Slip fits: apply around the leading edge of the male part and the inside of the female part, and use a rotating motion during assembly to spread it.
- Press fits: apply thoroughly to both surfaces and assemble at high press-on rates.
- Shrink fits: coat to a smooth even film. Heating the female part — coat the male. Cooling the male part — coat the female. Doing both — apply to the cooled part, and avoid condensation on it.
- Do not disturb the parts until handling strength is reached.
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.
- Disassembly: hand tools first; if needed apply localised heat to about 250°C and take apart while hot. If that temperature is not possible, heat as far as you can and use mechanical aids.
- Store unopened and dry, ideally 8°C to 21°C; outside 8–28°C the properties can be affected.
- Do not return decanted product to the original container.
Loctite 603 or 638?
Both are high strength; the difference is viscosity and gap. 603 is thin (100–150 mPa·s) and belongs in tight slip fits where a thick product cannot reach the joint. 638 is thick (2,500 mPa·s) and fills gaps approaching 0.25 mm, which is what rescues a worn housing. Measure the clearance first: tight and clean-ish → 603; worn and open → 638. For bearings that must come off again, use 641.
Always read the current technical and safety data before use —
ask us and we'll send it with your quotation.
