Spot And Plug Weld Nugget Size: BMW/Mini

Spot And Plug Weld Nugget Size: BMW/Mini

Did you know that many OEMs specify nugget size for spot and plug welds? This information is typically found within vehicle-specific repair procedures or can be found under general welding guidelines. Let’s see what BMW/Mini has to say.

BMW/Mini welding requirements can typically be found in the document Welding Steel Components. A search for the document title or a search for "welding" will bring up this document on the service site.

The Welding Steel Components document states that squeeze-type resistance spot welding (STRSW) and GMA (MIG) welding are both acceptable for repairs and clarifies with the following:

  • "Take the number and position of welding spots and MAG weld seams from the separated part. Replace areas inaccessible to spot-welding tongs with MAG plug welds at the same distance.
  • Diameter of bores for plug welding is 8 mm."

This means that when performing repairs, welds should be replaced in the same location and in the same quantity that was used from the factory.

STRSW tip size and squeeze force are not specified, but the document does state the following: "To determine the optimum electrode contact force for spot-welding, carry out spot-weld shear tests on sample sheet metal."

The document goes on to state:

  • "During MAG welding, the weld gap must be kept as small as possible. The larger the weld gap, the lower will be the strength of the joint.
  • In order to keep the electron flow short during MAG welding on the body, you must if possible, attach the ground terminal directly to the component to be welded.
  • Minimum distance between welding spots 25 mm."

The general welding information found in the Welding Steel Components document does not replace vehicle-specific OEM procedures. If a different attachment method is identified in an OEM procedure, that is the attachment method that must be used.

Following OEM welding requirements, including what nugget size is required, will help ensure a complete, safe, and quality repair.

For additional BMW/Mini information, check out the following pages:
BMW OEM Information
Mini OEM Information

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