Steel Spot And Plug Weld Nugget Size: Mitsubishi - UPDATE

Did you know that some 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 Mitsubishi has to say.

Information on spot welds and plug welds can typically found in two areas of Mitsubishi vehicle-specific service manuals.

Spot Welding

Mitsubishi does not indicate a specific spot weld nugget size in their collision repair information.

Spot weld information is located under: Service Manual ➤ 9-Base of Body Repair ➤ Welding ➤ Electric Resistance Spot Welding. Here Mitsubishi provides a simple formula for determining the diameter of the spot welding tip to be used and a chart to determine the number of spot welds required based on panel thickness. In addition, the document also states the following:

• "Make the spot welds at the center of the flanges to provide sufficient adhesion.
• The number of spot weld points should be the same as, or slightly more than the number of original repair welds.
• If the total thickness of the plates at the weld places is 3 mm (0.12 inch) or more, use plug welding because spot welding will not provide sufficient welded strength.
• When spot welding three or more panels together, if painted surfaces cause a loss of conductivity, make the welds at the same places as the factory welds. If this is done, extra welds will not be necessary, but if extra welds are necessary, switch to plug welding."

Mitsubishi Spot Welding Requirement/Recommendation

Mitsubishi does not indicate a spot welding vs. plug welding preference in their collision repair information.

Plug Welding

Mitsubishi does not indicate a specific plug weld nugget size in their collision repair information.

Plug weld information is located under: Service Manual ➤ 9-Base of Body Repair ➤ Welding ➤ Gas Shield Arc Welding. Mitsubishi states the following:

• "In order to prevent the formation of blowholes, fill in each hole completely in one pass.
• Be sure the two panels are in perfect contact.
• Be sure the penetration goes all the way to the bottom panel.
• Plug welding is done by making holes 5-6 mm (0.2-0.24 inch) in diameter in one of the panels to be welded together."

Where the spot weld and plug weld nugget size was not identified, refer to the Steel Spot And Plug Weld Nugget Size: UPDATE article. This article provides general guidelines.

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

For additional Mitsubishi information, check out the Mitsubishi OEM information page.

Additional I-CAR Collision Repair News you may find helpful:

• Back-To-Basics: Destructive Weld Testing
• Collision Information Website Access: Mitsubishi
• Dressing GMA Welds
• Steel Spot And Plug Weld Nugget Size: UPDATE
• Step-By-Step: Accessing Mitsubishi Repair Information
• Weld-Through Primer Guidelines: Mitsubishi - UPDATE
• Welding And MIG Brazing Hotspot

---

Related I-CAR Courses

Course Introduction to Squeeze-Type Resistance Spot Welding

Course Squeeze-Type Resistance Spot Welding Hands-On Skills Development

Course Steel GMA Welding Theory

Course Training and Certification: Steel GMA Welding

Course Welding Training and Certification