Perfect TIG welding

Stainless steel chain products are used very widely.
Are these chains really safe?

[Table-1] Tensile test results SUS304 wire diameter 5mm chain

Breaking load

Table 1 shows that chain with a remarkably low breaking load is being sold.

Their external appearances are similar, so why are the test results so different?

See the sectional photographs of the weld sections.
sectional photographs of the weld sections Photograph 1
sectional photographs of the weld sections
Photograph 2
sectional photographs of the weld sections
After the weld section is cut and the cutting plane is washed with acid, the color of the welded part changes. Sectional photograph of weld section of chain made by our company Sectional photograph of weld section of imported chain made by C

* The discolored part in the center is the weld section.

Photographs 1 and 2 are sectional photographs of weld sections.
Comparing photographs 1 and 2 shows that the fusion depth of the weld section is shallower.

The fusion depth is shallower, which means that the chain link is not fully connected.

Tensile test sample
Photograph 3
Tensile test sample
Photograph 4
Tensile test sample
Chain made by our company after tensile test (Break location is on the end at the left.) Imported chain made by C after tensile test (Break location is on the end at the left.)

Photo 4 shows that the chain broke before being stretched.
A chain is made by connecting individual links. Each link must be securely welded.

If the welding of even one link of a chain is defective, it can cause a truly disastrous accident.