Back to basics: Squeeze-type resistance spot welder maintenance

Sometimes, the key to a successful repair is revisiting the fundamentals. Proper maintenance of a squeeze-type resistance spot welder (STRSW) plays a critical role in ensuring consistent performance and maintaining the equipment to its designed specifications. 

While spot welders vary by manufacturer, most share common wear points that require regular inspection and maintenance, including: 

• Electrode tips 

• Arm contact points 

• Coolant 

• Coolant connections 

• O-rings 

Over time, electrode tips can deform, become thinner, or develop pitting. When tips become oversized, weld strength is often compromised. Electrode tips should be replaced whenever their shape, size, or surface condition begins to affect weld quality or prevent the machine from calibrating correctly. In some cases, tips can be restored using reshaping tools provided by the equipment manufacturer. 

Arm contact points should be inspected whenever the welding arms are changed. These surfaces must be clean and free of damage, as they are responsible for transferring electrical current to the arm. Maintaining good contact is essential to ensure the correct current reaches the electrode tip and produces a quality weld. 

Coolant levels should be checked before each use and topped up as required. Manufacturers may specify different coolant types, couplers, and O-rings, so it is important to follow the recommendations outlined in the equipment manual. The manual should also provide maintenance intervals and replacement part numbers. If this information is unavailable, contact your supplier for guidance. 

A few minutes spent on routine maintenance can help prevent costly downtime, improve weld quality, and extend the life of your equipment. 

To learn more about welding best practices and repair procedures, explore the I-CAR Canada course catalogue!