660 Quick Metal Retaining Compound, Press Fit Repair. 38651. 50mL Tube. Loctite 660 Quick Metal Retaining Compound, Press Fit Repair is a creamy, non-running adhesive/sealant. Repairs worn machine parts. Restores correct fit to mating assemblies. Fills gaps up to 0.020" diametral clearance. Typical Applications: Refitting worn shafts. Housings. Coupling and form-in-place shims. Repairing worn keyways. Loose set screws and other severely worn parts.