Loctite 638 is a one-component anaerobic shaft-bush locker, used to stick cylindrical parts. Loctite 638 is especially suitable during assembly of metal parts, when the gap between them is no more than 0.25 mm. Loctite 638 polymerizes when there is no air between metal surfaces. It prevents loose attachments (connections) from knocks and vibrations. NSF product is allowed for use in food production. Application. The product is used to lock cylindrical parts with the gaps up to 0.25 mm, especially when highly strong connection is required at a room temperature. It is used to lock bushes and pins in the housings and shafts. The best resistance to dynamic, axial, and radial loads. It is ideally suitable for shafts, gears, pulleys, and other cylindrical parts. It is certified for the contact with food: P1 NSF Reg. Nr.: 123010, DVGW-Freigabe (EN 751-1): NG-5146AR0619, WRC-Freigabe (BS 6920): 0511518. Urethane methacrylate.