ALPAR piercing clamp Al-Cu 16-120/16-120 double-sided with break-off nut

ALPAR piercing clamp Al-Cu 16-120/16-120 double-sided with break-off nut is a mechanical connector designed to create a reliable electrical and mechanical joint between aluminum and copper conductors. The double-sided configuration accepts conductors with cross-sections from 16 mm² up to 120 mm² on both sides and incorporates a shear (break-off) nut to ensure consistent torque during installation. This clamp is intended for use in power distribution, overhead lines and service connections where a secure Al-to-Cu transition is required.

Advantages

The clamp provides a stable low-resistance electrical connection between aluminum and copper conductors without the need to strip insulation in many cases, reducing installation time. Its double-sided design enables symmetrical connections and straightforward conductor routing. The break-off nut limits applied torque to a preset value, improving installation consistency and reducing the risk of over-tightening that can damage conductors. Constructed from materials suitable for dissimilar metal connections, it helps limit galvanic corrosion when installed according to recommended practices.

Suitable for

• Creating Al-to-Cu electrical transitions on overhead and service lines
• Power distribution networks where conductor cross-sections range from 16 mm² to 120 mm²
• Repair, splice or tap applications requiring a mechanical clamp with defined torque control
• Field installations where rapid, repeatable connections are needed

When it may not be suitable

This piercing clamp is not intended for conductors outside the specified cross-section range (below 16 mm² or above 120 mm²) and should not be used where insulation or environmental sealing requirements demand a fully encapsulated connector. It is also not suitable where code or application requires welded, brazed, or permanently insulated joints instead of mechanical clamps.

Key specifications

• Conductor compatibility: aluminum to copper
• Acceptable conductor cross-section per side: 16–120 mm²
• Design: double-sided piercing clamp
• Torque control: break-off (shear) nut for preset tightening
• Primary use: power distribution, overhead and service lines

How to use

Position the clamp so each conductor lies in its respective channel and align conductors for correct seating. Tighten the shear nut evenly until it breaks off at the specified torque, ensuring the clamp teeth pierce conductor surfaces and establish contact. Verify mechanical retention and electrical continuity after installation. Follow standard safety practices, de-energize circuits when required, and comply with local regulations and utility procedures.

What to consider before purchase

• Confirm conductor materials and cross-sections fall within 16–120 mm² for both sides
• Verify that a mechanical piercing clamp is acceptable for your application and local regulations
• Ensure installation tools and clearance allow safe torque application and shear nut operation
• Consider environmental exposure and whether additional sealing or protection is required

Usage recommendations

For reliable long-term performance, install on clean conductors, apply the recommended torque until the break-off nut shears, and inspect connections periodically for signs of corrosion or loosening. Use appropriate personal protective equipment and follow utility guidelines for Al-to-Cu joints.