Loctite 680 High Strength Retaining Compound 250ml

Loctite 680 is a one-component, green, high strength anaerobic retaining compound. It is a methacrylate ester designed for the bonding of cylindrical fitting parts.

It works on active metals and on passive surfaces such as stainless steel and plated parts, and it tolerates minor surface contamination from cutting, lubrication, anti-corrosion and protection fluids. This is the 250ml pack.

Where this product is used

• Bonding cylindrical fitting parts, such as pins and collars
• Steel, stainless steel and aluminium parts (all tested by Henkel)
• Passive surfaces such as stainless steel and plated parts
• Parts with minor oil contamination from cutting or lubrication fluids
• Assemblies that can be released with standard hand tools

Features

• High strength: 26 N/mm² on steel pins and collars after 7 days at 22 °C
• Medium viscosity class, 750 to 1,750 mPa·s
• Green liquid with positive fluorescence under UV light
• One component, no mixing
• Removable with standard hand tools; heat to about 250 °C if needed
• Certified to ANSI/NSF Standard 61 for potable water systems not exceeding 82 °C (regional approval)
• Cold strength tested to -75 °C

Key specifications

Selecting the right option

The same compound is also supplied in a smaller pack: Loctite 680 High Strength Retaining Compound 50ml. For a medium strength grade see Loctite 641 Retaining Compound, and for high strength with high temperature performance see Loctite 648 High Strength, High Temperature Retaining Compound 50ml.

Henkel recommends an activator to speed cure or where gaps are large: Loctite 7471 Primer T Surface Preparation Activator Aerosol 133g or Loctite SF 7649 Activator for Anaerobic Adhesives 133ml.

Using it

Henkel gives no fixture time. Cure speed is shown as graphs and depends on the materials, the gap and the temperature. Strength is still building between 24 hours and 7 days.

To speed cure, or where large gaps are present, use an activator.

Disassemble with standard hand tools. If needed, apply local heat to about 250 °C and take the parts apart while hot.

Storage and handling

Store unopened in a dry location, optimally between 8 °C and 21 °C. Storage below 8 °C or above 28 °C can adversely affect the properties of the product.

Limits and safety

Not normally recommended on plastics, particularly thermoplastics, where stress cracking could result; confirm compatibility. Not recommended for pure oxygen or oxygen-rich systems, or as a sealant for chlorine or other strong oxidising materials. Read the safety data sheet before use.

Frequently asked questions

What strength does Loctite 680 reach?

On steel pins and collars it reaches 26 N/mm² compressive shear after 7 days at 22 °C (ISO 10123). Stainless steel reaches 28 N/mm² and aluminium 16 N/mm².

How do I remove a part bonded with Loctite 680?

Use standard hand tools. If that fails, apply local heat to about 250 °C and pull apart while hot.

Is Loctite 680 approved for potable water?

Henkel states it is certified to ANSI/NSF Standard 61 for commercial and residential potable water systems not exceeding 82 °C. Henkel describes this as a regional approval; contact AIMS if you need confirmation for a specific application.

What is the viscosity of Loctite 680?

750 to 1,750 mPa·s (Brookfield RVT, spindle 3, 20 rpm, 25 °C). Henkel classes it as Medium.

What is the fixture time of Loctite 680?

The Henkel data sheet gives no fixture time. Cure speed is shown as graphs; on steel the minimum is 19.3 N/mm² at 24 hours and the typical value is 26 N/mm² at 7 days (22 °C).

What breakaway torque does Loctite 680 give?

35 N·m on M10 black oxide bolts and mild steel nuts, cured 24 hours at 22 °C (ISO 10964).

Related products

See also: Loctite 680 High Strength Retaining Compound 50ml, Loctite 641 Retaining Compound, Loctite 648 High Strength, High Temperature Retaining Compound 50ml, Loctite 7471 Primer T Surface Preparation Activator Aerosol 133g, Loctite SF 7649 Activator for Anaerobic Adhesives 133ml.