Pintejin specializes in custom sheet metal fabrication service and more. Advanced china engineering team and machinery is what sets us apart from our competitors.Contact us(via [email protected]) to learn more about our capabilities and how we can serve you.

How to repair wrinkles and bumps in car sheet metal parts?

Wrinkles and concavities and convexities caused by impact or extrusion by external force, such as minor damage and no extension of the metal, belong to elastic deformation. The heavier, the metal will expand, which is a plastic deformation. Tearing occurs when the impact or crush is particularly severe. The exposed parts of the body sheet metal parts may have wrinkles and concave-convex damage.

Convex trimming:

For the repair of convex surfaces with large curvature, see that for concave-convex damage, hammering method or top-pulling method can be used to repair. For minor concave-convex damage, the pad iron can be placed on the back of the lower part of the recess, hit with a hammer, and the position of the pad iron can be changed accordingly.

When the convex part is basically knocked flat, the concave part will mostly recover due to the reaction force of the horn. Then observe the overall smoothness of the board surface, and make some subtle trimmings in a targeted manner to repair the concave and convex damage.

Larger depressions:

You can use a backing plate to cushion the back of the depression, and directly lift it up with a jacking tool.

In order to reduce the jacking force, if necessary, the concave part can be heated to dark red. Rebound should be considered when ejecting, which can make it “overkill”. If there are large ductile protrusions on the surface, the metal at the extension can be properly shrunk. If it is difficult to put the horn in the damaged part, drill holes in the concave part with as few holes as possible and the hole diameter as small as possible, then fold it into a hook shape with iron wire, fasten it from the hole, and then apply external force to stretch it until it meets the requirements. When required, pull out the wire, weld the hole, and grind it flat.

Wrinkle damage repair

For fold damage, an external force (opposite to the impact force) can be applied to the fold to transform the unfolding of the fold into concave-convex damage. Then use the concave-convex damage repair method to repair. A manual hoist can be used as a repair tool for automobile sheet metal parts. One end is fixed at the fold of the sheet metal part, and the other end is fixed on a solid column and wall. The guide chain is tightened, and the folds are gradually unfolded. The degree of extension should be observed at any time to avoid tearing.

Automotive Sheet Metal Fabrication

Pintejin Sheet Metal shop offers a cost-effective solution for a wide range of industries with our custom metal stamping and custom sheet metal fabrication capabilities. Our stampnig operations include a variety of sheet-metal forming manufacturing processes, such as punching, blanking, embossing, bending, flanging, and coining. Our professional, experienced and well-trained engineers can execute the complex metal stamping operations with precision and accuracy.

No matter what your metal fabrication needs are, Pintejin can offer the right solution: from single sheet metal part or sub-assembly of stamped metal parts to turnkey solutions for mechanical and electrical assemblies. We have the technology, equipment and the experience to fabricate customised metal products from aluminium sheet metal fabrication, steel, zinc plated steel, stainless steel sheet metal fabrication, brass and copper. Designs that require CNC machining of surfaces or components can be accommodated. We can supply polished, galvanized, zinc coated or powder coated finishes for any sheet metal work or stamped metal components. Coupled with our accurate and reliable metal fabricating equipment, we guarantee precision and repeatability in custom sheet metal work. You’ll be taking advantage of the best sheet metal fabrication china can produce.


With Pintejin automated and highly streamlined sheet metal fabrication service, you can expect a sheet metal fabrication quote within 12 hours and lead times as quickly as three days.Our rapid prototyping offering also includes a solid and reliable manufacturing capability (led by our expert team with 15+ years of experience) and technical and quality assurance, including SGS and RoHS material certifications, in-process quality reports, and First Article Inspection.



  • Automotive Sheet Metal
  • Electronic Sheet Metal
  • IPC Sheet Metal
  • LED Light Sheet Metal Parts
  • Laser Cutting China

Sheet Metal Fabricator