Steel Spot and Plug Weld Nugget Size: Nissan/INFINITI

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 Nissan/INFINITI has to say.

Nissan/INFINITI provides spot weld and plug weld information in the Fundamentals category of newer vehicle-specific service manuals. This information is also available as a separate document titled Body Repair Manual - Fundamentals - 2015 Edition.

Once logged into the Nissan service site, to access this publication:

  1. Click on View Nissan Publications
  2. Select Body Repair Manual from the Publication Type dropdown
  3. Leave all other dropdowns as Any
  4. Click Search
  5. Locate the Body Repair Manual - Fundamentals - 2015 Edition from the list of results
  6. Click on the blue Eye icon to the right

Note: This document is only found on the Nissan service site. Per our contact at Nissan/INFINITI: "This edition is to be used for INFINITI vehicles."

Spot Welds

Per the category Fundamentals Guide - Body Welding And Precautions in the newer vehicle-specific manual: "Generally, the capacity of repair shop spot welding machines is smaller than that of factory welding machines. Accordingly, the number of points of spot welding should be increased by 20% - 30%. Note: The number of spot weld points in the NISSAN/INFINITI service manuals have already increased 20% - 30% compared to the factory welds. Avoid welding over previously welded areas."

The fundamentals document provides a chart that lists various panel thicknesses and what welding pitch is required.

Nissan/INFINITI Spot Welding Requirement/Recommendation

Per our contact at Nissan/INFINITI: "If the spot welding arms can reach, the steel is 980 MPa or lower, and the spot welder parameters (found in the vehicle-specific manuals) are followed, then spot welding may be used instead of the plug welds that are shown in the replacement procedure."

In newer vehicle-specific service manuals, there is an area called Ultra High Strength Steel (UHSS) Welding, that states when welding steel higher than 980 MPa: “Never spot weld ultra-high strength steel of tensile strength more than 980 MPa. For this type of ultra-high strength steel, perform plug welding.” That means if 1,500 MPa steel is being welded, plug welding is the only option. If 980 MPa or lower steel is being welded, then spot welding or plug welding may be done.

Plug Welds

Both documents include a plug weld hole diameter chart that determines the size of the hole based on panel thickness. This chart is found in the Partial Replacement Of Panel (Welded Panel) area of the Fundamentals document and Repairing Procedures and Precautions - Preparation For Service Panel Installation in the Body Repair Manual - Fundamentals - 2015 Edition.

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