Loctite 660 High-Strength Retaining Compound – Large Gap Repair
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Regular price
$ 43.99 USD
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LOCTITE® 660 is a one-part, high-strength anaerobic retaining compound for repairing worn cylindrical metal assemblies without re-machining. Its metallic-gray, thixotropic paste fills larger gaps and is well suited to worn bearing seats, shafts, keys, splines, tapers, and retaining shims.
Why choose LOCTITE 660
- Restores fits on worn cylindrical metal parts without re-machining
- High-strength, very high-viscosity formula with excellent gap cure
- Fills diametrical gaps from 0.25–0.50 mm (0.01–0.02 in.)
- Helps resist loosening and leakage caused by shock and vibration
- One-component formula—no mixing required
Popular applications
- Worn bearing seats and spun bearings
- Damaged keyways, keys, and splines
- Slip-, press-, and shrink-fitted cylindrical assemblies
- Retaining shims and repairing worn shafts or tapers
Technical specifications
| Technology / chemistry | Acrylic; urethane methacrylate |
|---|---|
| Cure | Anaerobic; secondary cure with activator |
| Appearance | Metallic-gray paste |
| Components | One component |
| Viscosity at 25 °C | 150,000–350,000 mPa·s (cP) at 5 rpm; 1,000,000–2,000,000 mPa·s (cP) at 0.5 rpm |
| Fixture time | 15 minutes (typical; substrate, gap, and temperature affect cure) |
| Gap fill | 0.25–0.50 mm (0.01–0.02 in.) |
| Compressive shear strength | ≥17.2 N/mm² (2,490 psi) on steel pins and collars after 24 hours at 22 °C, ISO 10123 |
| Operating temperature | -55 to 150 °C (-65 to 300 °F) |
| Specific gravity | 1.13 at 25 °C |
| Package | 50 mL tube; Henkel IDH 135527; legacy item 66040 |
Application and cure guidance
- Clean and dry the internal and external metal surfaces.
- On inactive metals, at low temperature, or when faster cure is needed, apply LOCTITE SF 7471 or SF 7649 and allow it to dry.
- For slip fits, apply around the leading edge of the pin and inside the collar, then assemble with a rotating motion. For press fits, coat both bond surfaces and assemble promptly.
- Do not disturb the parts until sufficient handling strength develops. Full performance is typically evaluated after 24 hours at room temperature.
Important limitations: Not recommended for pure oxygen or oxygen-rich systems, chlorine, or other strong oxidizers. It is not normally recommended for plastics, especially thermoplastics that may stress-crack; test compatibility before use. Gaps larger than 0.50 mm should be rebuilt with an appropriate metal-filled repair compound.