Cause: Poor Mechanical Connection

Weld system components are loose due to wear or improperly applied fasteners.

Description 

Correct replacement parts and procedures should be used when maintaining weld equipment in order to keep all joints secure. Thermal cycling, vibrations, etc. may loosen mechanical connections. Assembly and torque of the bolts, washers, nuts, etc. must meet manufacturers’ specifications.

Detection 

Poor mechanical connections may be detected from one of the following:

• Cracks & holes
• Expulsion/burn through
• Inconsistent weld quality
• Poor Class A appearance
• Stuck weld
• Undersized weld
• Visible looseness of welder components
• Looseness detected by manually moving the equipment

Significance 

Quality, Workplace Issues, Cost, Downtime, Maintenance, Throughput (cycle time; PPH), are all potentially affected by this condition.

Subordinate Causes

• Improper maintenance
• Improper bolt torque
• Improper shunt length