Correct Cable Lugs Crimping

Guide to Ensure Correct Crimping of Cable Lugs

A Better Way to Crimp Safely, Every Time

1. Clean Thoroughly Before You Crimp

Prepare the conductor: Use a wire brush to remove debris and oxidation—especially important for aluminium wires. Clean surfaces prevent contact corrosion.
Strip the insulation correctly: Use a high-quality wire stripper and strip about 10% longer than the lug’s insertion depth—this anticipates the material stretch during crimping.

2. Use an Integrated System: Lug, Tool & Die from the Same Manufacturer

Match the cable lug, crimping tool, and dies within one manufacturer’s system for compatibility and perfect fit. This avoids increased contact resistance and prevents overheating—or even fire hazards.
Always inspect dies before use: they should be clean and shiny, with well-defined profiles.

3. Crimp in the Right Sequence

For cable lugs: Begin at the junction near the terminal tongue and work towards the cable end. This allows material expansion and prevents cracks.
For splice connectors: Start crimping in the centre to allow uniform material flow and prevent splitting.

4. Follow Markings for Correct Number of Presses

Many lugs (e.g., DIN 46235 lugs) include markings indicating how many crimps are needed—follow these exactly for reliable connections.

5. Choose the Right Tool for Your Application

Manual tools: Ideal for small-to-medium cross-sections and lighter workloads.
Hydraulic or battery-powered tools: Better for heavy usage, larger conductors, or high-volume tasks.
Choose tools with proper force, one-handed operation, and even force distribution like joystick-synchronised dies.
Opt for tools with pressure indicators or integration to confirm a full crimp—mechanical or hydraulic.

6. Confirm Your Crimp – Conduct Inspection & Testing

Visual checks:
- Ensure the crimp is even, smooth, and fully compressed.
- Look for die code imprints on the barrel as evidence of correct tooling used.
Mechanical checks:
- Perform a light pull test to confirm the conductor is secure.
Electrical checks:
- Use tools like thermal imaging or low-resistance ohmmeters to detect hot spots or poor connections.
Avoid over- or under-crimping—both create vulnerabilities like raised wings or internal voids, which can lead to failure.

7. Stick to Standards & Routine Maintenance

Follow standards like BS?7609, BS?7727, DIN 46235, DIN 48083, and IEC 61238 for consistent, safe connections.

Tools need to be regularly calibrated and maintained, with documentation to meet safety and QA requirements.

Best Practices: Keep It Clean & Keep It Safe

Practice	Why It Matters
Clean conductor	Prevents corrosion; ensures electrical integrity
Use proper die/tool	Ensures consistent compression and reliability
Follow crimp direction	Reduces risk of cracks and mechanical failures
Inspect & test	Verifies safety, prevents malfunction
Maintain tools	Ensures precision and compliance