Repair Overview - Repair Guidelines for High-Strength Steel Parts
1. Repair Guidelines for High-Strength Steel Parts
High strength steel is defined as any steel with a tensile strength of 340 MPa or higher.
Ultra high strength steel is defined as any steel with a tensile strength of 980 MPa or higher. If a part is constructed of, or includes, high-strength steel, observe the following important guidelines:


Body and Frame Straightening Guidelines

High-strength steel is more rigid and has more memory than traditional steel, making it more difficult to straighten. To prevent further body damage when using frame straightening equipment, apply pulling force gradually and closely monitor body dimensions during the straightening process to ensure the body dimensions are returned to the proper specifications. High strength steel parts over 590 MPa must not be straightened. These parts should be replaced with new parts if damaged.

NOTE: Do not apply heat, such as an oxyacetylene torch, to any body part during straightening. This may compromise the internal structure and high-strength steel parts. Any of these parts that had heat applied to them during straightening MUST be replaced with new parts. Ignoring these instructions may significantly reduce occupant protection in any subsequent collision.





Removing spot welds

Use a spot weld cutter or drill bit designed for high-strength steel to remove spot weld nuggets from the steel parts being removed. If the cutting performance of the spot cutter decreased, grind the spot cutter using a grinder as soon as possible. Or change the spot cutter to a new one. Decreased cutting performance unnecessarily increase cutting time and generates heat that may compromise the internal structure of high-strength steel parts.

NOTE: In order to protect the blade of the spot cutter, mark the center of the spot welding nugget using a center punch and grind the edge of the nugget to be flat using a belt sander (about P60) and then begin the cutting work. Apply the specific cutting oil to protect the blade during the cutting work.