LOCTITE 638 is a high strength retaining compound. It is designed for the bonding of cylindrical fitting parts. The product is especially suited for use on narrow bond gaps, approaching 0.25 mm. It cures at room temperature when confined between close-fitting metal surfaces. The curing process occurs in the absence of air.
LOCTITE 638 prevents loosening and leakage caused by shock and vibration. It works on active metals and passive substrates (e.g. stainless steel) alike. The product offers high-temperature performance and good oil tolerance. It also withstands minor surface contaminants. Typical applications include locking bushings and sleeves into housings and on shafts.
- High temperature resistance
- Tolerates minor contaminants, including industrial oils
- Provides good strength on all metals, including passive substrates
- Ideal for shafts, gears, pulleys and similar cylindrical parts
- P1 NSF Reg. No.: 123010
- DVGW Approval (EN 751-1): NG-5146AR0619
- WRAS Approval (BS 6920): 0511518
How to use Loctite 638:
- For best results, clean surfaces with a LOCTITE® solvent. Allow it to dry.
- If using on inactive metal or curing speed is too slow, use an activator spray such as LOCTITE® SF 7471 or SF 7649. Allow it to dry.
- For slip fitted assemblies. Apply adhesive around the leading edge of the pin and the inside of the collar. Use a rotating motion during assembly to ensure good coverage.
- For press fitted assemblies. Apply adhesive thoroughly to both bond surfaces. Assemble at high press on rates.
- For shrink fitted assemblies. Apply adhesive onto the pin. Heat collar to create sufficient clearance for free assembly. Hold together or clamp bonds until the adhesive has fixtured.
- Allow LOCTITE® 638 to develop full strength before subjecting to any service loads. This will usually take about 24 hours.
Store LOCTITE® 638 in the unopened container in a dry location. Optimal Storage: 8° C to 21° C. Storage below 8° C or greater than 28° C can adversely affect product properties.