Description
LOCTITE 638 is designed for the bonding of cylindrical fitting parts, particularly with narrow bond gaps approaching 0.25 mm. The product cures when confined in the absence of air between close-fitting metal surfaces. Prevents independent loosening and leaks due to shocks and vibrations.
- Volume: 250ml bottle (Loctite no. 1803042)
- Also available in: 10ml bottle, 50ml bottle
Application
- It not only works on active metals but also on passive substrates, exhibiting robust cure performance.
- The product offers high-temperature performance and good oil tolerance, and tolerates minor surface contaminants.
Characteristics
- High temperature resistance
- Tolerates minor contaminants, including industrial oils
- High strength on all metals, including passive substrates (e.g. stainless steel)
- Ideal for shafts, gears, pulleys and similar cylindrical parts
- Fixture Time: 4 min
Certification
- DVGW Approval (EN 751-1): NG-5146AR0619
- WRAS Approval (BS 6920): 0511518
Technical Information
| Agency Approvals / Specifications | DVGW (EN 751-1): NG-5146AR0619, NSF P1 Reg No: 123010, WRAS (BS 6920): 0511518 |
| Color | Green |
| Diametrical Clearance (Maximum) | 0.25 mm |
| Fixture Time | 4 min. |
| Fixture Time Temperature | 39 °F |
| Full Cure Temperature | 77 °F |
| Gap Fill | 0.01 in. |
| Shear Strength Unit, Steel | psi |
| Shear Strength, Steel | 4500 |
| Specific Gravity | 1.09 g/l |
| Specific Gravity Temperature | 25 °C |
| Substrates | Metal: Steel |
| Temperature | -65 – 300 °F |
| Viscosity | 2500 mPa.s (cP) Brookfield |
| Viscosity Temperature | 77 °F |
Hazard Information (CLP)

Signal word: Danger
Hazard Statements (H-phrases)
- H315: Causes skin irritation.
- H317: May cause an allergic skin reaction.
- H318: Causes serious eye damage.
- H335: May cause respiratory irritation.
- H412: Harmful to aquatic life with long lasting effects.
Precautionary Statements (P-phrases)
Prevention:
- P273: Avoid release to the environment.
- P261: Avoid breathing vapors.
- P280: Wear protective gloves/eye protection.
Response:
- P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing.
- P302+P352: IF ON SKIN: Wash with plenty of soap and water.
- P333+P313: If skin irritation or rash occurs: Get medical advice/attention.
For Consumer Use:
- P101: If medical advice is needed, have product container or label at hand.
- P102: Keep out of reach of children.
- P501: Dispose of contents/container in accordance with national regulation.
Additional Information
No additional hazards if used properly.
Henkel AG & Co. KGaA, Henkelstr. 67, 40589 Düsseldorf, GERMANY, +49 211 7970, [email protected], www.henkel.com






Sarah –
Easy to use, no mess at all. Excellent product, worth every cent. Super fast delivery, thank you. Packaging was slightly damaged, but product is excellent.
yann_fr –
Well made and durable. Top product, would definitely recommend. Exactly as described.
daniela89 –
Not too big, not too small, just perfect. Easy to use, without making a mess. I noticed the difference right away! Perfect for my needs; I’m very satisfied.
maja.bln –
Perfect for my needs, couldn’t be happier. Very fast delivery, thank you. Packaging was slightly damaged, but the product is excellent.
Laurent L. –
Fast shipping and good quality. Exactly what I needed. Works just as advertised.
jannis88 –
Great service, thank you. Arrived right away, excellent service.
Anna V. –
Not too big, not too small, just right. Perfect for my needs; I’m very satisfied. Very effective, I noticed a change in just a week.
Delphine U. –
Very satisfied, better than expected. It completely solved my problem! I noticed a difference after a short time! Surprisingly good quality for the price.